Optical layered body, method for producing optical layered body, polarizer and image display device

ABSTRACT

The present invention provides an optical layered body which stably keeps light resistance such as ultraviolet resistance and oxidation resistance while keeping conventional physical properties and optical properties as the outermost surface material of an image display device, which is excellent in an antistatic property and which is capable of providing high image contrast when employed for an image display device. The optical layered body has a light transmitting substrate and a resin layer formed on one surface of the light transmitting substrate and is characterized in that the resin layer contains a binder resin, a polythiophene, an auxiliary conductive agent, and a leveling agent.

RELATED APPLICATIONS

This application is a Continuation of application Ser. No. 13/697,462,filed on Nov. 12, 2012, which is the National Phase of PCT/JP2011/060982filed on May 12, 2011, and this application claims priority ofApplication No. 2010-110526 filed in Japan on May 12, 2010. The entirecontents of each application is hereby incorporated by reference.

TECHNICAL FIELD

The present invention relates to an optical layered body, a method forproducing an optical layered body, a polarizer, and an image displaydevice.

BACKGROUND ART

An optical layered body composed of functional layers having variousproperties such as an antiglare property, an antireflection property,and an antistatic property is formed on the outermost surface of animage display device such as a cathode ray tube display device (CRT), aliquid crystal display (LCD), a plasma display (PDP), anelectroluminescence display (ELD), a field emission display (FED), atouch panel, or electronic paper.

Such an optical layered body is generally required to havecharacteristics such as light resistance, that is, UV resistance andoxidation resistance since being set on the outermost surface of animage display device.

Conventionally, in an optical layered body, in order to prevent stainsdue to deposition of dust or the like because of charge or occurrence ofhindrance at the time of use or in the display production process, aresin layer containing an antistatic agent, which is a conductivematerial, is formed.

Materials known as an antistatic agent to be used for the opticallayered body are inorganic materials, e.g., conductive fine particles ofmetal oxides, for example, antimony-doped tin oxide (ATO), tin-dopedindium oxide (ITO), and the like, and carbon (Patent Literatures 1 and2). However, inorganic materials such as metal oxides have a problemthat if the addition amount is large, the light transmittance of anoptical layered body is reduced or that the contrast of an image isreduced in the case of installation in an image display device.

Materials also known as the antistatic agent are organic materials suchas conductive polymers and quaternary ammonium conductive materials(Patent Literature 2).

Patent Literature 3 discloses an antistatic resin compositioncharacterized by containing a soluble conductive polymer componentincluding a solubilized polymer component having an anionic group and/oran electron-withdrawing group in its molecule and a conductive polymercomponent, and a hard coat component.

Patent Literature 4 discloses a conductive polymer solutioncharacterized by containing a soluble conductive polymer componentincluding a solubilized polymer component having an unsaturated doublebond at the terminal of a side chain of a molecule and a conductivepolymer component, as well as a photocurable monomer and/or an organicsolvent.

Patent Literature 5 or 6 discloses a conductive polymer/dopantcomplex-containing organic solvent dispersion containing a conductivepolymer, a dopant, as well as a dispersant containing at least oneselected from the group consisting of amide compounds or amines having aradical polymerizable group and nonionic surfactants and having a watercontent of 20 wt. % or less.

However, in the case of using these organic conductive materials andantistatic resin compositions for producing an optical layered body, anoptical layered body having a desired antistatic property can beobtained, but it is impossible to obtain an optical layered body whichhas a sufficiently high contrast of an image while keeping conventionalphysical characteristics (hard coat property and the like) and opticalcharacteristics (light transmitting property, antiglare property and thelike).

Recently, further improvement of the quality of a display image isdesired and it is required to realize an optical layered body which cangive a higher contrast of an image.

Patent Literatures 5 and 6 disclose usability of polythiophenes asconductive polymers. However, since having no ultraviolet resistance andoxidation resistance, polythiophenes are inconveniently deteriorated inthe antistatic property in the case a composition containingpolythiophenes is used for producing an optical layered body.

CITATION LIST Patent Literature

-   -   Patent Literature 1: Japanese Kokai Publication 2008-032845    -   Patent Literature 2: Japanese Kokai Publication 2006-023350    -   Patent Literature 3: Japanese Kokai Publication 2005-350622    -   Patent Literature 4: Japanese Kokai Publication 2006-028439    -   Patent Literature 5: Japanese Kokai Publication 2008-222850    -   Patent Literature 6: Japanese Kokai Publication 2008-045116

SUMMARY OF THE INVENTION Technical Problem

In view of the above state of the art, it is an object of the presentinvention to provide an optical layered body which stably keeps lightresistance such as ultraviolet resistance and oxidation resistance whilekeeping conventional physical properties and optical properties as theoutermost surface material of an image display device, which isexcellent in an antistatic property and production stability and whichis capable of providing high image contrast when employed for an imagedisplay device.

Solution to Problem

The present invention provides an optical layered body having a lighttransmitting substrate and a resin layer formed on one surface of thelight transmitting substrate, in which the resin layer comprises abinder resin, a polythiophene, an auxiliary conductive agent, and aleveling agent.

The optical layered body of the present invention preferably has acontent of the polythiophene of 0.1 to 1.0 part by weight relative to100 parts by weight of the binder resin.

The polythiophene preferably contains an anionic compound.

The auxiliary conductive agent is preferably at least one kind selectedfrom the group consisting of chain-like metal oxide particles, carbonnanotubes, and conductive fine particles.

The auxiliary conductive agent is preferably chain-like metal oxideparticles and/or conductive fine particles and the content of theauxiliary conductive agent is preferably 0.5 to 5.0 parts by weightrelative to 100 parts by weight of the binder resin.

The auxiliary conductive agent is preferably carbon nanotubes and thecontent of the auxiliary conductive agent is preferably 0.001 to 0.13parts by weight relative to 100 parts by weight of the binder resin.

The optical layered body of the present invention preferably has aninitial surface resistance value and a surface resistance value after alight resistance test of the resin layer of less than 1×10¹²Ω/□.

The resin layer preferably further contains an additive having aprotonic functional group.

The additive having a protonic functional group is preferably epoxyacrylate.

The resin layer preferably has an antiglare function.

The resin layer preferably has a region containing no auxiliaryconductive agent from the interface on the opposite side to the lighttransmitting substrate to 100 nm.

The optical layered body of the present invention preferably further hasa rough surface under coat layer on the light transmitting substrate andthe resin layer formed on the rough surface under coat layer.

The present invention also provides a method for producing an opticallayered body having a light transmitting substrate and a resin layerformed on one surface of the light transmitting substrate, wherein themethod includes a step of forming the resin layer using a resin layercomposition comprising a binder resin, a polythiophene, an auxiliaryconductive agent, a leveling agent, and a solvent.

In the method for producing an optical layered body of the presentinvention, the content of water in the resin layer composition ispreferably 20 wt. % or less.

The present invention also provides a polarizer having a polarizingelement, wherein the polarizer has the optical layered body on a surfaceof the polarizing element.

The present invention also provides an image display device having theoptical layered body or the polarizer on an outermost surface.

Hereinafter, the present invention will be described in detail.

The present invention provides an optical layered body having a lighttransmitting substrate and a resin layer formed on one surface of thelight transmitting substrate, in which the resin layer comprises aspecified component. Accordingly, the optical layered body of thepresent invention can stably keep light resistance such as ultravioletresistance and oxidation resistance while keeping conventional physicalproperties (hardness, hard coatability, and the like) and opticalproperties (light transmitting property, antiglare property, and thelike) as an outermost surface material of an image display device, isexcellent in an antistatic property and is capable of providing highimage contrast when employed for an image display device.

Specifically, in the optical layered body of the present invention, theresin layer is a layer comprising a binder resin, a polythiophene, anauxiliary conductive agent, and a leveling agent.

Since the resin layer contains such specified components, even if thecontent of the polythiophene in the resin layer is low in the opticallayered body of the present invention, the optical layered body has highconductivity and shows an excellent antistatic property. Since thecontent of the polythiophene in the resin layer can be reduced, theoptical layered body of the present invention can maintain a high lighttransmitting property. In the case the optical layered body of thepresent invention is employed for an image display device, the opticallayered body can improve the contrast of an image to be displayed. Sincecontaining the auxiliary conductive agent, the resin layer is providedwith improved ultraviolet resistance and oxidation resistance whilekeeping the above-mentioned excellent properties.

The optical layered body of the present invention is also excellent inproduction stability. In this description, “production stability” meansthat there is little uneveness of initial surface resistance value in aplane of the resin layer.

The way of employing the optical layered body of the present inventionfor a device such as an image display device is necessary to beapplication in a large size of more than 1 m² and the optical layeredbody needs to be mass-produced. In the case of production in such a way,the properties in a plane of the resin layer may become uneven due tounevenness of coating thickness and dispersion unevenness of the coatingliquid and it is sometimes impossible to obtain desired propertiesstably in a plane. In this case, the production manner is unsuitable formass production and the productivity cannot be stabilized. Contrarily,since particularly a polythiophene and an auxiliary conductive agentexist in a desired state in the resin layer, the optical layered body ofthe present invention is provided with a stabilized surface resistancevalue at the initial stage and after a light resistance test and also aninitial surface resistance value stable in a plane.

The polythiophene in the optical layered body of the present inventionis a component functioning as an antistatic agent for providingconductivity to the resin layer and may be a substituted orunsubstituted one.

The polythiophene can give sufficient conductivity to a resin layer asbeing unsubstituted. However, in order to improve the conductivity, itis preferable to introduce a functional group such as an alkyl group, acarboxyl group, a sulfo group, an alkoxy group, a hydroxy group or acyano group into the molecule.

Specific examples of the polythiophene include poly(thiophene),poly(3-methylthiophene), poly(3-ethylthiophene),poly(3-propylthiophene), poly(3-butylthiophene), poly(3-hexylthiophene),poly(3-heptylthiophene), poly(3-octylthiophene), poly(3-decylthiophene),poly(3-dodecylthiophene), poly(3-octadecylthiophene),poly(3-bromothiophene), poly(3-chlorothiophene), poly(3-iodothiophene),poly(3-cyanothiophene), poly(3-phenylthiophene),poly(3,4-dimethylthiophene), poly(3,4-dibutylthiophene),poly(3-hydroxythiophene), poly(3-methoxythiophene),poly(3-ethoxythiophene), poly(3-butoxythiophene),poly(3-hexyloxythiophene), poly(3-heptyloxythiophene),poly(3-octyloxythiophene), poly(3-decyloxythiophene),poly(3-dodecyloxythiophene), poly(3-octadecyloxythiophene),poly(3,4-dihydroxythiophene), poly(3,4-dimethoxythiophene),poly(3,4-diethoxythiophene), poly(3,4-dipropoxythiophene),poly(3,4-dibutoxythiophene), poly(3,4-dihexyloxythiophene),poly(3,4-diheptyloxythiophene), poly(3,4-dioctyloxythiophene),poly(3,4-didecyloxythiophene), poly(3,4-didodecyloxythiophene),poly(3,4-ethylenedioxythiophene), poly(3,4-propylenedioxythiophene),poly(3,4-butenedioxythiophene), poly(3-methyl-4-methoxythiophene),poly(3-methyl-4-ethoxythiophene), poly(3-carboxythiophene),poly(3-methyl-4-carboxythiophene),poly(3-methyl-4-carboxyethylthiophene), andpoly(3-methyl-4-carboxybutylthiophene). Especially,poly(3,4-ethylenedioxythiophene) is preferable since it is excellent incompatibility with a binder resin.

The polythiophene is preferably a complex with an anionic compound(hereinafter, also referred to as a polythioiphene complex).

The anionic compound may be those having, as an anionic group, afunctional group which may cause chemical oxidation doping of thepolythiophene. In terms of production easiness and stability, especiallypreferable examples include a mono-substituted sulfuric acid estergroup, a mono-substituted phosphoric acid ester group, a phosphoric acidgroup, a carboxyl group, and a sulfo group. In terms of the effect ofdoping the polythiophene component with the functional group, morepreferable examples include a sulfo group, a mono-substituted sulfuricacid ester group, and a carboxyl group.

Specific examples of the anionic compound include polyvinylsulfonicacid, polystyrenesulfonic acid, polyallylsulfonic acid, poly(ethylacrylate)sulfonic acid, poly(butyl acrylate)sulfonic acid,poly-2-acrylamide-2-methylpropanesulfonic acid, polyisoprenesulfonicacid, polyvinylcarboxylic acid, polystyrenecarboxylic acid,polyallylcarboxylic acid, polyacrylcarboxylic acid,polymethacrylcarboxylic acid,poly-2-acrylamide-2-methylpropanecarboxylic acid, polyisoprenecarboxylicacid, and poly(acrylic acid). The anionic compound may be homopolymersor copolymers of two or more kinds of them. Preferable examples amongthem include polystyrenesulfonic acid, polyisoprenesulfonic acid,poly(ethyl acrylate)sulfonic acid, and poly(butyl acrylate)sulfonicacid.

The polymerization degree of the anionic compound is not particularlylimited and it is preferable, for example, that the number of a monomeris 10 to 100000. In terms of solvent solubility and conductivity, thelower limit is preferably 50 and the upper limit is preferably 10000.

The polythiophene complex can be obtained by, for example, oxidationpolymerization of a precursor monomer of the polythiophene with theanionic compound, an oxidizing agent, an oxidation catalyst, and asolvent.

Examples of the oxidizing agent and oxidation catalyst includeperoxodisulfuric acid salts such as ammonium peroxodisulfate, sodiumperoxodisulfate, and potassium peroxodisulfate; transition metalcompounds such as ferric chloride, ferric sulfate, ferric nitrate, andcupric chloride; metal halides such as boron trifluoride and aluminumchloride; metal oxides such as silver oxide and cesium oxide; peroxidessuch as hydrogen peroxide and ozone; organic peroxides such as benzylperoxide; and oxygen.

The solvent is not particularly limited and examples include polarsolvents such as water, N-methyl-2-pyrrolidone, N,N-dimethylformamide,N,N-dimethylacetamide, dimethyl sulfoxide, hexamethylene phosphoryltriamide, acetonitrile, and benzonitrile; phenols such as cresol,phenol, and xylenol; alcohols such as methanol, ethanol, propanol, andbutanol; ketones such as acetone and methyl ethyl ketone; carboxylicacids such as formic acid and acetic acid; carbonate compounds such asethylene carbonate and propylene carbonate; ether compounds such asdioxane and diethyl ether; chain ethers such as ethylene glycol dialkylether, propylene glycol dialkyl ether, polyethylene glycol dialkylether, and polypropylene glycol dialkyl ether; heterocyclic compoundssuch as 3-methyl-2-oxazolidinone; and nitrile compounds such asacetonitrile, glutarodinitrile, methoxyacetonitrile, propionitrile, andbenzonitrile. These solvents may be used alone or in form of a mixtureof two or more of them or by mixing with another organic solvent.

In the oxidation polymerization, the mixing ratio of the precursormonomer of the polythiophene to the anionic compound is not particularlylimited. Since a polythiophene complex to be obtained is provided withsufficient conductivity, the mixing ratio is preferably 0.5 to 5 partsby weight of the anionic compound to 1 part by weight of thepolythiophene.

A commercially available product can be used as the polythiophenecomplex and examples include CLEVIOS P (trade name, manufactured by H.C. Stark) and Orgacon (trade name, manufactured by Agfa). Especially,CLEVIOS P (trade name, manufactured by H. C. Stark), which is a complexof poly(3,4-ethylenedioxythiophene) and polystyrenesulfonic acid, ispreferable since having good compatibility with a resin.

Many of the complexes obtained by oxidation polymerization andcommercially available products are aqueous dispersions. In the presentinvention, a polythiophene complex in form of an organic solventdispersion is preferable.

An organic solvent for the polythiophene complex in form of an organicsolvent dispersion is not particularly limited as long as the solventdoes not dissolve the polythiophene. Examples include alcohols, ketones,ethers, amides, sulfoxides, sulfones, esters, and nitriles.

The alcohols are not particularly limited as long as having a hydroxylgroup. Examples include monoalcohols such as methanol, ethanol,propanol, isopropanol, and butanol; dialcohols such as ethylene glycol,propylene glycol, and polypropylene glycol; and polyhydric alcohols suchas glycerin and pentaerythritol.

The ketones are not particularly limited as long as having a ketonestructure in a molecule. Examples include acetone, methyl ethyl ketone,and methyl isobutyl ketone. The ethers are not particularly limited andexamples include ethers such as diethyl ether, ethyl isopropyl ether,dioxane, tetrahydrofuran, polyethylene glycol dialkyl ethers, andpolypropylene glycol dialkyl ethers.

The amides are not particularly limited and examples includedimethylformamide and N-methylpyrrolidone.

The sulfoxides are not particularly limited and examples includedimethyl sulfoxide.

The sulfones are not particularly limited and examples includesulfolane.

The esters are not particularly limited and examples include methylacetate and ethyl acetate.

The nitriles are not particularly limited and examples includeacetonitrile and propionitrile.

These solvents may be used alone or two or more of them may be used incombination.

Especially, alcohols such as ethanol, isopropanol, and ethylene glycoland ketones such as methyl ethyl ketone and methyl isobutyl ketone arepreferable in terms of the handling property and dispersion stability.

The content of the polythiophene in the resin layer is preferably 0.1 to1 parts by weight relative to 100 parts by weight of the solid contentof a binder resin, which will be described later. If the content is lessthan 0.1 parts by weight, it is sometimes impossible to give a desiredantistatic property. If the content exceeds 1 part by weight, the lighttransmittance is decreased and it is sometimes impossible to realize adesired high contrast. The lower limit of the content of thepolythiophene is preferably 0.2 parts by weight and the upper limit ispreferably 0.7 parts by weight.

Since the optical layered body of the present invention exhibits anantistatic property although the content of the polythiophene is so low,it is assumed that the polythiophene is not dispersed in the entireresin layer but exists in a layer-like state at a certain position inthe resin layer or exists in a fine mesh-like state in the resin layer.Herein, the layer-like state is assumed to be a state where thepolythiophene exists in a layer-like state while being evenly dispersedat a position where electric communication can be kept and also a statewhere the polythiophene exists in a layer-like state while localizedsmall portions are at positions so close to one another as to keepelectric communication. The fine mesh-like state is assumed to be astate where the polythiophene composes a mesh while molecules of thepolythiophene exist adjacently to one another and keep electriccommunication in the entire resin layer. The polythiophene may exist inthe above-mentioned state while being mediated with an auxiliaryconductive agent described later in the resin layer.

It is also assumed that the polythiophene exists in the resin layerclose to the surface side of the resin layer (opposite to the surface ofthe light transmitting substrate) but not at a position in the outermostsurface for satisfying the light resistance.

The auxiliary conductive agent is a component for assisting thepolythiophene to exhibit the antistatic property in the optical layeredbody of the present invention.

As described above, it is assumed that the polythiophene exists at aposition in the resin layer close to the surface of the resin layer butnot in the outermost surface. In the case the resin layer contains onlythe polythiophene, if the existence position is too close to theoutermost surface, the resin layer may be deteriorated by ultravioletrays or oxidation to possibly make the surface resistance in a planeuneven and deteriorate the antistatic property (that is, resin layer maybe inferior in the light resistance). On the other hand, if thepolythiophene exists at a position where deterioration by ultravioletrays or deterioration by oxidation is scarcely caused, that is, at aposition far from the outermost surface of the resin layer, electriccommunication to the surface of the resin layer becomes difficult andthe surface resistance may possibly become high or uneven in a plane andit also results in inferiority of the antistatic property. If thepolythiophene does not exist in a fine mesh-like state evenly in theresin layer, the surface resistance of the resin layer becomes uneven ina plane and the resin layer may possibly become inferior in theantistatic property. Particularly, in the case the resin layer containsonly the polythiophene, in order to produce an even and fine mesh-likestate of the polythiophene, the addition amount is required to be madelarge and besides, adequate adjustment is also required in theprocessing condition.

However, in the present invention, since an auxiliary conductive agentis added to the resin layer in addition to the polythiophene, theproblems which may possibly be caused in the case of containing only thepolythiophene can be advantageously prevented and the optical layeredbody is thus excellent in the production stability.

Herein, even if the resin layer contains an auxiliary conductive agent,if the auxiliary conductive agent is evenly dispersed in the whole resinlayer in a state of having no electric communication of the agentitself, no electric communication net of the auxiliary conductive agentis formed and thus the antistatic property may become insufficient. Ifthe auxiliary conductive agent in an amount enough to exhibit thesufficient antistatic property is added, the light transmitting propertyis deteriorated and it may possibly result in impossibility in realizinga desired high contrast. Therefore, it is preferable that the auxiliaryconductive agent is dispersed at electrically communicable positions inthe resin layer and forms an electric communication net. In the presentinvention, it is also preferable that an electric communication net isformed by the auxiliary conductive agent and the polythiophene.

The resin layer preferably has a region in which no auxiliary conductiveagent exists from the interface on the opposite side to the lighttransmitting substrate to the depth of 100 nm. Deterioration of thelight resistance can be preferably prevented by forming such a region inthe defined range where no auxiliary conductive agent exists.

Herein, the above-mentioned “region where no auxiliary conductive agentexists” means a case where no auxiliary conductive agent is observed ina region of 100 nm from the interface opposite to the light transmittingsubstrate in a SEM image of a cross section of the resin layer, or acase where the number of molecules of the auxiliary conductive agentobserved in the area of about 5 μm in the direction perpendicular to thethickness direction of the resin layer is 2 or less in an imagemagnified 10000 times of a cross section of the resin layer near theinterface opposite to the light transmitting substrate.

In the optical layered body of the present invention, it is assumed thatthe auxiliary conductive agent exists, for example, from the interfacein the light transmitting substrate side to immediately under theposition where the polythiophene exist in the resin layer (configuration1); that the auxiliary conductive agent exists at the position same asthe position where the polythiophene exists (configuration 2); and thatthe auxiliary conductive agent exists in a region from the position sameas the position where the polythiophene exists to the interface of theresin layer in the light transmitting substrate side (configuration 3).

In the configuration 1, as shown in FIG. 3, it is assumed that a region32 where the auxiliary conductive agent exists and a region 31 where thepolythiophene exists are formed sequentially in layers from theinterface of a resin layer 30 in the light transmitting substrate side.In the configuration 1, it is assumed that the auxiliary conductiveagent assists the antistatic property of the polythiophene by layeringthe region 32 where the auxiliary conductive agent exists and the region31 where the polythiophene exists and forming electric communicationbetween these regions. In FIG. 3, the region 32 where the auxiliaryconductive agent exists is formed up to the interface in the lighttransmitting substrate side; however, it is not necessary that theregion 32 where the auxiliary conductive agent exists is formed up tothe interface in the light transmitting substrate side.

In the configuration 2, as shown in FIG. 4, it is assumed that a region41 where the polythiophene and the auxiliary conductive agent exist isformed in a resin layer 40. In the configuration 3, as shown in FIG. 5,it is assumed that a region 51 where the polythiophene and the auxiliaryconductive agent exist is formed in a resin layer 50 and a region 52where the auxiliary conductive agent exists is formed adjacently to theregion 51 in the light transmitting substrate side. In theconfigurations 2 and 3, it is assumed that the polythiophene and theauxiliary conductive agent form an electric communication net in theseregions where these materials exist in the resin layer and the auxiliaryconductive agent thus assists the antistatic property of thepolythiophene.

In FIG. 5, the region 52 where the auxiliary conductive agent exists isformed up to the interface in the light transmitting substrate side;however, it is not necessary that the region 52 where the auxiliaryconductive agent exists is formed up to the interface in the lighttransmitting substrate side.

FIGS. 3 and 4 are cross-sectional views schematically showing theregions where the auxiliary conductive agent and the polythiophene existin the resin layer in the optical layered body of the present invention.

In the case there are points where the polythiophene is deteriorated byultraviolet rays or the like, it is assumed that the auxiliaryconductive agent exists at the deteriorated points. As a result, it isassumed that the surface resistance value of the resin layer surface ismade more excellent and the uneveness in a plane can be reduced andfurther the light resistance such as ultraviolet resistance andoxidation resistance of the polythiophene can be improved.

As a result, it is assumed that the surface resistance value of theresin layer surface can be made more excellent and the uneveness in aplane can be reduced and further the light resistance such asultraviolet resistance and oxidation resistance of the polythiophene canbe improved.

The “uneveness in a plane” means that the surface resistance value ofthe resin layer surface is uneven in a plane of the resin layer.

FIG. 1 shows a cross sectional SEM photograph of an optical layered bodyof the present invention having a resin layer containing chain ATO asthe auxiliary conductive agent. Since the addition amount of thepolythiophene in the present invention is extremely small, it ispresently difficult to observe the polythiophene by observing a crosssectional SEM photograph of the optical layered body of the presentinvention; however, it is assumed that the polythiophene existspreferably in the resin layer as described above.

As shown in FIG. 1, the existence position of the auxiliary conductiveagent such as chain ATO contained in the resin layer can be confirmed byobserving the cross section of the resin layer. The optical layered bodyof the present invention shown in FIG. 1 has a structure in which theresin layer is formed on a rough surface under coat layer containingorganic fine particles.

The auxiliary conductive agent is preferably at least one kind selectedfrom the group consisting of chain-like metal oxide particles, carbonnanotubes, and conductive fine particles.

The chain-like metal oxide particles may be metal oxide particles havinga structure of being connected in a chain-like form. The chain-likemetal oxide particles are chain-like conductive inorganic fine particleshaving conductivity.

The average particle diameter of metal oxide particles composing thechain-like metal oxide particles is preferably 1 to 100 nm and morepreferably 5 nm as the lower limit and 80 nm as the upper limit. If theaverage particle diameter is smaller than 1 nm, the grain boundaryresistance of the metal oxide particles is sharply increased andthree-dimensionally agglomerated fine particles tend to increase whilescarcely forming the chain-like metal oxide particles, which maysometimes result in impossibility of obtaining a resistance low enoughto exhibit the function as an auxiliary conductive agent. On the otherhand, if the average particle diameter exceeds 100 nm, formation of thechain-like metal oxide particles becomes difficult and even if theformation is possible, since the contact points of the metal oxideparticles are lessened, it may sometimes result in impossibility ofobtaining a resistance low enough to exhibit the function as anauxiliary conductive agent. Further, the light absorption by the metaloxide particles is increased and it may sometimes result in decrease ofthe light transmittance and increase of the haze of the resin layer. Forthis reason, if the thickness of the resin layer is made small or theamount of the metal oxide particles is reduced to provide the resinlayer with constant light transmittance, it may sometimes becomeimpossible to obtain sufficient conductivity as an auxiliary conductiveagent.

The average length of the chain-like metal oxide particles is preferably2 to 200 nm and more preferably 5 nm as the lower limit and 80 nm as theupper limit. If the average length is shorter than 2 nm, the contactresistance of the chain-like metal oxide particles is increased and theantistatic property of the optical layered body of the present inventionmay sometimes become insufficient. On the other hand, if the averagelength is longer than 200 nm, the formability of the resin layer isdeteriorated and the optical layered body of the present invention mayhave a problem of optical characteristics such as haze and theappearance may be worsened in some cases.

The average particle diameter and average length of the metal oxideparticles are values measured by a scanning electron microscope (JMS5300, manufactured by JEOL Ltd.).

The chain-like metal oxide particles preferably have an aspect ratio of2 to 200 in terms of satisfying both of the antistatic property and thelight transmittance. If the aspect ratio is lower than 2, the antistaticproperty of the optical layered body of the present invention cannot bemade sufficiently excellent and if it exceeds 200, the lighttransmittance of the resin layer may sometimes be reduced.

The aspect ratio is a value measured by measuring the longer axis andshorter axis of the chain-like metal oxide particles using a publiclyknown electron microscope and dividing the length of the longer axiswith the length of the shorter axis. The longer axis of the chain-likemetal oxide particles means a straight line between two points on theouter circumference of the chain-like metal oxide particles whosedistance is the longest and the shorter axis of the chain-like metaloxide particles means a straight line between two points on the outercircumference of the chain-like metal oxide particles whose distance isthe longest in a direction perpendicular to the longer axis.

Specific examples of the metal oxide particles composing the chain-likemetal oxide particles include metal oxide particles of one or moreelements selected from the group consisting of Au, Ag, Pd, Cu, Ni, Ru,Rh, Sn, In, Sb, Fe, Pt, Ti, Cr, Co, Al, Zn, Ta, Pb, Os, and Ir.

Especially, since being capable of more preferably improving theantistatic property of the optical layered body of the presentinvention, those preferably used as the metal oxide particles are tinoxide, tin oxide doped with Sb, F, or P, indium oxide, indium oxidedoped with Sn or F, antimony oxide, and low valence titanium oxide, andparticularly, ATO (antimony tin oxide) is preferably used.

The chain-like metal oxide particles can be prepared by, for example,the following method.

That is, first, an alcohol solution containing 0.1 to 5 wt. % of a metalsalt or metal alkoxide is hydrolyzed by heating. At this time, ifnecessary, the solution may be added to hot water or an alkali may beadded. The hydrolysis gives a gel dispersion of a metal hydroxide with aprimary particle diameter of 1 to 100 nm.

Next, the gel dispersion is filtered and washed and the metal hydroxideis subjected to an autoclave treatment in the presence of an organicstabilizer if necessary and further to a mechanical dispersiontreatment. In this case, ionic impurities may be removed by carrying outan ion exchange resin treatment.

The chain-like metal oxide particles obtained in such a manner are takenout of the dispersion generally by centrifugation or the like after theproduction and washed with an acid or the like if necessary andthereafter used by being dispersed in a polar solvent. The dispersioncontaining the obtained chain-like metal oxide particles may be used asa coating liquid as it is.

The mechanical dispersion treatment may be performed by, for example, asand mill method, an impact dispersion method, or the like andparticularly, an impact dispersion method is preferably employed. Theimpact dispersion method is a method of colliding a slurry against awall at a speed as high as the sound speed for dispersing or crushingand is carried out by using an apparatus such as Artimizer or Nanomizer.

Examples of the organic stabilizer include gelatin, poly(vinyl alcohol),polyvinylpyrrolidone, polycarboxylic acids such as oxalic acid, malonicacid, succinic acid, glutaric acid, adipic acid, sebacic acid, maleicacid, fumaric acid, phthalic acid, and citric acid, and salts thereof,heterocyclic compounds, and mixtures of these compounds.

Examples of the polar solvent include water; alcohols such as methanol,ethanol, propanol, butanol, diacetone alcohol, furfuryl alcohol,tetrahydrofurfuryl alcohol, ethylene glycol, and hexylene glycol; esterssuch as acetic acid methyl ester and acetic acid ethyl ester; etherssuch as diethyl ether, ethylene glycol monomethyl ether, ethylene glycolmonoethyl ether, ethylene glycol monobutyl ether, diethylene glycolmonomethyl ether, and diethylene glycol monoethyl ether; and ketonessuch as acetone, methyl ethyl ketone, acetyl acetone, and acetoaceticacid esters. These polar solvents may be used alone or two or more ofthe solvents may be used in combination.

The carbon nanotubes may be those having a monolayer structure as longas they have a structure in which carbon hexagonal net planes arecylindrically closed, those having a multilayer structure, that is,cylindrical structures are so arranged as to form a multiple nestedstructure, or a mixture of them.

Specific examples of the carbon nanotubes include single wall carbonnanotubes, double wall carbon nanotubes, and multi-wall carbonnanotubes. Examples of the carbon nanotubes also include those partiallyentwisted like ropes or those having branched structures. Inconsideration of the cost, multi-wall carbon nanotubes are preferable.

Carbon nanotubes may be used as they are produced; however, those withimproved purity by removing impurities are preferable. Examples of themethod known as a purification method of carbon nanotubes include amethod of heating the carbon nanotubes in vacuum and a method ofsubjecting the carbon nanotubes to an acid treatment, and it is alsoknown that an acid treatment produces hydroxyl groups or carboxyl groupsin the side chains of carbon nanotubes.

The size of the carbon nanotubes is not particularly limited; however,the fiber length is preferably 100 nm to 100 μm and the fiber diameteris preferably 1 nm to 1 μm. If the fiber length is shorter than 100 nm,the surface resistance value of the resin layer may become uneven in aplane and the antistatic property may sometimes be deteriorated. If thefiber length exceeds 100 μm, the light transmittance may sometimes bereduced. The fiber length is more preferably 1 μm as the lower limit and10 μm as the upper limit and the fiber diameter is more preferably 200nm as the upper limit.

The fiber length and fiber diameter of the carbon nanotubes are valuesmeasured by electron microscopic observation.

The conductive fine particles may be metal fine particles or metal oxidefine particles. Examples of a material composing the conductive fineparticles include tin oxide (SnO₂), antimonyl oxide (Sb₂O₅), antimonytin oxide (ATO), indium tin oxide (ITO), aluminum zinc oxide (AZO),fluoro-tin oxide (FTO), ZnO, Au, Ag, Cu, Al, Fe, Ni, Pd, and Pt.

The conductive fine particles are preferably spherical and the particlediameter is preferably 0.1 to 200 nm. If the particle diameter issmaller than 0.1 nm, the antistatic property of the present inventionmay not be sufficiently improved and if it exceeds 200 nm, thetransparency (total light transmittance) of the optical layered body ofthe present invention may sometimes be reduced. A more preferable lowerlimit is 20 nm and a more preferable upper limit is 150 nm.

In the optical layered body of the present invention, the content of theauxiliary conductive agent may be properly determined in accordance withthe kind of the auxiliary conductive agent to be used and in the casethe auxiliary conductive agent is chain-like metal oxide particlesand/or conductive fine particles, it is preferably 0.5 to 5.0 parts byweight relative to 100 parts by weight of the binder resin. If thecontent is less than 0.5 parts by weight, the antistatic property of theoptical layered body of the present invention may sometimes becomeinsufficient and if it exceeds 5.0 parts by weight, the lighttransmittance of the optical layered body of the present invention maysometimes be reduced and the contrast may be reduced. The content ismore preferably 0.5 to 2.5 parts by weight. The antistatic property ofthe optical layered body of the present invention can be improved morepreferably if the content of the auxiliary conductive agent is withinthe above-mentioned range.

If the auxiliary conductive agent is carbon nanotubes, the content ofthe auxiliary conductive agent is preferably 0.001 to 0.13 parts byweight relative to 100 parts by weight of the binder resin. If thecontent is less than 0.001 parts by weight, the antistatic property ofthe optical layered body of the present invention may sometimes becomeinsufficient and if it exceeds 0.13 parts by weight, the lighttransmittance may sometimes be reduced and the contrast may be reduced.A more preferable lower limit is 0.005 parts by weight and a morepreferable upper limit is 0.05 parts by weight. The antistatic propertyof the optical layered body of the present invention can be improvedmore preferably if the content of the auxiliary conductive agent iswithin the above-mentioned range.

In the optical layered body of the present invention, the binder resinis not particularly limited as long as it is a material which does notreact on the anionic compound and it preferably contains a hydrophobicresin. If the binder resin contains a hydrophobic resin, the opticallayered body is provided with an excellent antistatic property and highcontrast.

In this description, the “hydrophobic resin” means an acrylic acid esterresin containing no hydrophilic functional group such as a hydroxylgroup, an amino group, a carboxyl group, or a sulfo group but contains ahydrophobic functional group such as a vinyl group, a urethane group, ora (meth)acryloyl group.

In the optical layered body of the present invention, a resin whichreacts on an anionic compound cannot be used as the binder resin sincethe resin deteriorates the function of the antistatic property.

As the hydrophobic resin, especially urethane acrylate is preferablyusable since being suitable for providing an excellent antistaticproperty and high contrast and at the same time providing desirable hardcoatability.

In the optical layered body of the present invention, if the binderresin is used in combination with the urethane acrylate, the binderresin preferably contains a hydrophobic resin other than the urethaneacrylate. If the hydrophobic resin is further added, it is made possibleto make the polythiophene unevenly exist near the surface (the surfacein the opposite side to the light transmitting substrate) in the resinlayer and even if the addition amount of the polythiophene is small, anexcellent antistatic property can be provided. The reason for this isnot necessarily apparent, but it is supposed that existence of a largeamount of hydrophobic resins with low polarity in the resin layer makeslocalization of the polythiophene with high polarity in the near thesurface easy.

Specifically, preferable examples of the hydrophobic resin other thanurethane acrylate include (meth)acrylic esters such as pentaerythritoltetra(meth)acrylate, trimethylol propane tri(meth)acrylate, anddipentaerythritol hexa(meth)acrylate, and ethylene oxide-modifiedcompounds of these.

Pentaerythritol tetra(meth)acrylate is especially preferably used amongthem.

A hydrophobic resin with high polarity sometimes deteriorates theinitial antistatic property and for example, pentaerythritoltri(meth)acrylate is unsuitable.

The content of a hydrophobic resin in the binder resin is preferably 20to 100 wt. % in the resin components of the binder resin. If the contentis less than 20 wt. %, the antistatic property of the optical layeredbody of the present invention may be deteriorated. The content of thehydrophobic resin is more preferably 25 wt. % as the lower limit and 70wt. % as the upper limit.

The binder resin other than the hydrophobic resin may contain anionizing radiation-hardenable resin which is hardened by ultravioletrays or an electron beam, a mixture of an ionizing radiation-hardenableresin and a solvent drying resin (a resin that forms a coating film onlyby drying out the solvent added for adjusting the solid content at thetime of application), or a thermosetting resin. Especially, an ionizingradiation-hardenable resin is preferable.

Examples of the ionizing radiation-hardenable resin include compoundshaving one or more unsaturated bonds such as compounds having acrylatefunctional groups. Examples of a compound having one unsaturated bondinclude ethyl (meth)acrylate, ethylhexyl (meth)acrylate, styrene,methylstyrene, and N-vinylpyrrolidone. Examples of a compound having twoor more unsaturated bonds include reaction products of polyfunctionalcompounds and (meth)acrylate (e.g., polyhydric alcoholpoly(meth)acrylate esters) such as polymethylolpropanetri(meth)acrylate, hexanediol di(meth)acrylate, tripropylene glycoldi(meth)acrylate, diethylene glycol di(meth)acrylate, pentaerythritoltri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,6-hexanedioldi(meth)acrylate, and neopentyl glycol di(meth)acrylate.

Other than the above-mentioned compounds, those also usable as theionizing radiation-hardenable resin are polyester resins having anunsaturated double bond and a relatively low molecular weight, polyetherresins, acrylic resins, epoxy resins, alkyd resins, spiroacetal resins,polybutadiene resins, and polythiol-polyene resins.

A solvent drying resin to be used by mixing with the ionizingradiation-hardenable resin may be mainly a thermoplastic resin.

Addition of a solvent drying resin can effectively prevent a coatingfilm defect of a coating surface.

Specific and preferable examples of the thermoplastic resin includestyrene resins, (meth)acrylic resins, vinyl acetate resins, vinyl etherresins, halogen-containing resins, alicyclic olefin resins,polycarbonate resins, polyester resins, polyamide resins, cellulosederivatives, silicone resins, and rubber or elastomers.

Generally, it is particularly preferable to use a resin which isnoncrystalline and soluble in an organic solvent (especially, a commonsolvent capable of dissolving a plurality of polymers and hardenablecompounds) as the thermoplastic resin. Especially, a resin with highmoldability or film-formability, transparency, and weather resistance,for example, styrene resins, (meth)acrylic resins, alicyclic olefinresins, polyester resins, and cellulose derivatives (cellulose esters)are preferable.

Examples of the thermosetting resin include phenol resins, urea resins,diallyl phthalate resins, melamine resins, guanamine resins, unsaturatedpolyester resins, polyurethane resins, epoxy resins, aminoalkyd resins,melamine-urea co-condensed resins, silicon resins, and polysiloxaneresins.

The resin layer contains a leveling agent.

If the leveling agent is contained, the leveling agent bleeds to thesurface of the resin layer and therefore, in forming the resin layerusing a resin layer composition described later, defects such as unevenconvection in the resin layer composition or a Benard cell at the timeof application and drying can be prevented. Because of positive bleedingof the leveling agent to the resin layer surface, bleeding of thepolythiophene to the resin layer surface can be prevented and it isassumed to be made possible that the polythiophene can exist in alayer-like state at a certain position in the resin layer, or exist in afine mesh-like state in the resin layer, or exist at a position close tothe resin layer surface in the resin layer but not in the outermostsurface to provide a stable and desirable antistatic property.

The leveling agent is not particularly limited regardless of whether itis reactive or non-reactive as long as it is a material which does notreact on the anionic compound of the polythiophene and is preferably afluoro and/or silicon compound.

The fluorine compound preferably has a perfluoroalkyl group representedby C_(d)F_(2d+1) (d is an integer of 1 to 21), a perfluoroalkylene grouprepresented by —(CF₂CF₂)_(g)— (g is an integer of 1 to 50), or aperfluoroalkyl ether group represented by F—(—CF(CF₃)CF₂O—)_(e)—CF(CF₃)(e is an integer of 1 to 50) in combination with a perfluoroalkenylgroup such as CF₂═CFCF₂CF₂—, (CF₃)₂C═C(C₂F₅)—, or ((CF₃)₂CF)₂C═C (CF₃)—.

If the fluorine compound is a compound having the above-mentionedfunctional groups, the structure of the fluorine compound is notparticularly limited and a fluorine-containing polymer or a copolymer ofa fluorine-containing monomer and a fluorine-free monomer can also beusable. A fluorine compound particularly preferably used is a blockcopolymer or a graft copolymer consisting of a fluorine-containingpolymer segment composed of either of a homopolymer of afluorine-containing monomer, or a copolymer of a fluorine-containingmonomer and a fluorine-free monomer, and a fluorine-free polymersegment. In such a copolymer, the fluorine-containing polymer segmenthas a function of improving mainly a stain-proofing property, a water-and oil-repelling property and on the other hand, the fluorine-freepolymer segment has an anchor function of improving the compatibilitywith the binder component. Accordingly, in a reflection-preventinglaminated body using such a copolymer, even if the surface is repeatedlyscrubbed, the fluorine compound is hardly removed and the laminated bodykeeps these properties such as the stain-proofing property for a longduration.

The fluorine compound is available as a commercially available productand for example, Modiper F series produced by NOF Corporation andMegafac series produced by DIC Inc. are preferably used.

The silicon compound preferably has a structure represented by thefollowing formula:

wherein Ra is a C₁₋₂₀ alkyl group such as a methyl group; Rb is a C₁₋₂₀alkyl group unsubstituted or substituted with an amino group, an epoxygroup, a carboxyl group, a hydroxyl group, a perfluoroalkyl group, aperfluoroalkylene group, a perfluoroalkyl ether group, a or(meth)acryloyl group, a C₁₋₃ alkoxy group, or a polyether-modifiedgroup; Ra and Rb may be same or different; and m and n are respectivelyan integer of 0 to 200).

Polydimethylsilicone having a basic skeleton as shown in theabove-mentioned formula is generally known to have low surface tensionand be excellent in a water-repelling property and a mold releaseproperty and can be provided with another effect by introducing variouskinds of functional groups into side chains or terminals. For example,introduction of an amino group, an epoxy group, a carboxyl group, ahydroxyl group, a (meth)acryloyl group, an alkoxy group, or the like canprovide reactivity and a chemical reaction with the above-mentionedionizing radiation-hardenable resin composition can form a covalentbond. Further, introduction of a perfluoroalkyl group, aperfluoroalkylene group, or a perfluoroaklyl ether group can provide oilresistance, a lubricating property and the like and introduction of apolyether-modified group can improve the leveling property and thelubricating property.

Such a compound is available as commercially available products andvarious kinds of modified silicone oils suitable for the purposes, forexample, Silicone Oil FL 100 having a fluoroalkyl group (produced byShin-Etsu Chemical Co., Ltd) and Polyether-modified Silicone Oil TSF4460 (trade name, produced by Momentive Performance Materials, Japan)are available. Especially, TSF 4460 is preferably used in the presentinvention.

The fluorine and/or silicon compound may be a compound having astructure represented by the following formula:Ra_(n)SiX_(4-n)wherein Ra is a C₃₋₁₀₀₀ hydrocarbon group including a perfluoroalkylgroup, a perfluoroalkylene group, or a perfluoroalkyl ether group; X isa hydrolyzable group, for example, a C₁₋₃ alkoxy group such as a methoxygroup, an ethoxy group, or a propoxy group, an oxyalkoxy group such as amethoxymethoxy group or a methoxyethoxy group, or a halogen group suchas a chloro group, a bromo group, or an iodo group; all may be same ordifferent; and n is an integer of 1 to 3).

The hydrolyzable group makes formation of a covalent bond or a hydrogenbond with a hydroxyl group of particularly the inorganic component, thesilica component in the present invention, easy and is effective to keepthe adhesiveness.

Fluoroalkylsilane such as TSL 8257 (produced by GE Toshiba Silicone) isa specific example of such a compound.

The content of the leveling agent in the resin layer is preferably 0.01to 5 parts by weight relative to 100 parts by weight of the binderresin. If the content is less than 0.01 parts by weight, it may resultin defects such as uneven convection at the time of drying a coatingfilm or poor appearance of the coating surface due to levelinginsufficiency and therefore, it is not preferable. If the contentexceeds 5 parts by weight, it may result in defects such as decrease ofhardness of the coating film and therefore, it is also not preferable.The content of the leveling agent is more preferably 0.1 parts by weightas the lower limit and 2 parts by weight as the upper limit.

The resin layer preferably further contains an additive having aprotonic functional group.

Addition of the additive having a protonic functional group improvesdispersibility and stability of the polythiophene and makes the opticallayered body excellent in the antistatic property. This is supposedlyattributed to that the additive having a protonic functional group canact like the above-mentioned anionic compound. Addition of the additivehaving a protonic functional group is preferable since the lightresistance also is more stabilized.

Examples of the additive having a protonic functional group includeepoxy acrylate, hydroxyacrylate, and vinyl sulfonic acid. Especially,epoxy acrylate is preferable.

The content of the additive having a protonic functional group in theresin layer is preferably 1 to 15 parts by weight relative to 100 partsby weight of the binder resin. If the content is less than 1 part byweight, the polythiophene may possibly be agglomerated and precipitatedand additionally, the antistatic property may sometimes be deterioratedand the stable production may become difficult. If the content exceeds15 parts by weight, the polythiophene may possibly be dispersedexcessively and in this case, the antistatic property may bedeteriorated. The content of the additive having a protonic functionalgroup is more preferably 2 parts by weight as the lower limit and 10parts by weight as the upper limit.

The epoxy acrylate or the like, which is the additive having a protonicfunctional group, exhibits hard coatability by causing a crosslinkingreaction and functions also as a binder resin. In this case, the contentof the epoxy acrylate or the like is preferably 1 to 15 wt. % in 100 wt.% of the binder resin containing the epoxy acrylate or the like.

In the optical layered body of the present invention, the resin layerpreferably has an antiglare function.

The resin layer having an antiglare function preferably has an unevensurface shape. The uneven shape preferably has Sm, θa, Ra, and Rz asthose of an antiglare layer described later.

The uneven shape of the surface of the resin layer having an antiglarefunction may be formed by using a resin layer composition containing anantiglare agent, by phase separation of the binder resin, or byembossing process. Examples of the antiglare agent are same as those ofan antiglare agent described in the antiglare layer later.

The resin layer having the above-mentioned composition can be formed byusing a resin layer composition prepared by evenly mixing the binderresin, the polythiophene, the auxiliary conductive agent, the levelingagent, and if necessary the resin having a protonic functional group andother components in a solvent.

The mixing may be carried out with a publicly known apparatus such as apaint shaker, a bead mill, or a kneader.

The resin layer composition may further contain a photopolymerizationinitiator.

Examples of the photopolymerization initiator include acetophenones(e.g., trade name, Irgacure 184, 1-hydroxy-cyclohexyl-phenyl-ketoneproduced by Ciba (Japan) Ltd.; and trade name, Irgacure 907,2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, produced byCiba (Japan) Ltd.), benzophenones, thioxanthones, benzoin, benzoinmethyl ether, aromatic diazonium salts, aromatic sulfonium salts,aromatic iodonium salts, metallocene compounds, and benzoin sulfonicacid esters. These compounds may be used alone or two or more of themmay be used in combination.

The addition amount of the photopolymerization initiator is preferably0.1 to 10 parts by weight relative to 100 parts by weight of the solidcontent of the binder resin.

The resin layer composition may further contain other components ifnecessary. Examples of other components include an ultraviolet absorber,a stain-proofing agent, a refractive index adjustment agent, anantioxidant, a radical scavenger, a crosslinking agent, a hardeningagent, a polymerization promoter, a polymerization inhibitor, and aviscosity adjustment agent.

Examples of the solvent include alcohols (e.g., methanol, ethanol,propanol, isopropanol, n-butanol, sec-butanol, tert-butanol, benzylalcohol, PGME, and ethylene glycol), ketones (e.g., acetone, methylethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone,heptanone, diisobutyl ketone, and diethyl ketone), aliphatichydrocarbons (e.g., hexane and cyclohexane), halogenated hydrocarbons(e.g., methylene chloride, chloroform, and tetrachloromethane), aromatichydrocarbons (e.g., benzene, toluene, and xylene), amides (e.g.,dimethylformamide, dimethylacetamide, and n-methylpyrrolidone), ethers(e.g., diethyl ether, dioxane, and tetrahydrofuran), and ether alcohols(e.g., 1-methoxy-2-propanol). Especially, ethanol, isopropanol,n-butanol, ethylene glycol, and methyl isobutyl ketone are preferable.

One kind or a plurality of kinds of these solvents may be used andespecially, it is preferable that the entire solvent contains 5 to 70%of two or more kinds of alcohol solvents with different boiling points,and it is more preferable that the entire solvent contains 15 to 60% ofthem. If the alcohol solvents are contained in the above-mentionedrange, the antistatic property can be stably obtained.

A method of forming the resin layer may be a method of forming the resinlayer by applying the resin layer composition to form a coating film,drying the coating film if necessary, and thereafter hardening thecoating film.

As a method of forming a coating film by application, various publiclyknown methods such as a spin coating method, a dipping method, aspraying method, a die coating method, a bar coating method, a rollcoater method, a meniscus coater method, a flexo printing method, ascreen printing method, and a bead coater method can be mentioned.

A method of drying may be a method of drying the composition at 30 to120° C. for 3 to 120 seconds.

A hardening method for the coating film may be selected properly inaccordance with the contents of the composition and the like. If thecomposition is an ultraviolet hardenable one, the coating film may behardened by irradiation with ultraviolet rays.

In irradiation of ultraviolet rays, a method of radiating 10 to 300mJ/cm² of ultraviolet rays may be employed.

The thickness of the resin layer is preferably 0.6 to 10 μm. If thethickness is smaller than 0.6 μm, the hardness of the coating film maypossibly be insufficient. If the thickness is larger than 10 μm, unevenconvection in the coating film formed by applying the resin layercomposition cannot be suppressed sufficiently and it may possibly resultin impossibility of obtaining an optical layered body excellent in theantistatic property. The thickness is more preferably 1 to 9 μm. Thethickness of the resin layer is a value measured by observing a crosssection of the optical layered body with an electron microscope (SEM,TEM, or STEM).

The optical layered body of the present invention has a lighttransmitting substrate.

Those having smoothness and heat resistance and excellent in mechanicalstrength are preferable as the light transmitting substrate.

Specific examples of a material forming the light transmitting substrateinclude thermoplastic resins such as poly(ethylene terephthalate) (PET),poly(ethylene naphthalate), poly(butylene terephthalate), poly(butylenenaphthalate), triacetyl cellulose (TAC), cellulose diacetate, celluloseacetate butylate, polyamides, polyimides, polyethersulfones,polysulfones, polypropylene (PP), cycloolefin polymers (COP),cycloolefin copolymers (COC), polymethylpentene, poly(vinyl chloride),poly(vinyl acetal), polyether ketones, poly(methyl methacrylate),polycarbonates, and polyurethanes. Poly(ethylene terephthalate) ortriacetyl cellulose is preferable.

The thickness of the light transmitting substrate is preferably 20 to300 μm and more preferably 30 μm as the lower limit and 200 μm as theupper limit.

In order to improve the adhesiveness to a layer to be formed thereon,the light transmitting substrate may be subjected previously to aphysical treatment such as a corona discharge treatment, saponification,or an oxidation treatment, or application of an anchor agent or acoating agent such as a primer.

Since having the above-mentioned resin layer formed on the lighttransmitting substrate, the optical layered body of the presentinvention can stably keep light resistance such as ultravioletresistance and oxidation resistance while keeping conventional physicalproperties and optical properties as an outermost surface material of animage display device, is excellent in an antistatic property and iscapable of providing high image contrast when employed for an imagedisplay device. In the optical layered body of the present invention,the resin layer preferably has a function such as an antiglare propertyand hard coatability. The resin layer may be composed of a single layeror may have a multilayer structure.

The optical layered body of the present invention preferably has anantiglare function. The configuration of the optical layered body of thepresent invention having an antiglare function may be, for example, aconfiguration in which the resin layer has the antiglare function; or aconfiguration in which a rough surface under coat layer having an unevenshape is formed on the light transmitting substrate and the resin layeris formed on the rough surface under coat layer.

Having the antiglare function, the optical layered body of the presentinvention can prevent reflection of light from outside and improve thevisibility.

The optical layered body of the present invention preferably has aconfiguration of further having a rough surface under coat layer on thelight transmitting substrate and the resin layer on the rough surfaceunder coat layer. In the case the antiglare function is provided by amethod of, for example, mixing fine particles for formation of theuneven shape with the resin layer, the effect of the present inventionowing to the resin layer may possibly be lost depending on the existencestate of the fine particles for formation of the uneven shape oradequate processing conditions may possibly be required. However, if theresin layer is provided on the rough surface under coat layer, theoptical layered body of the present invention is provided with a properantiglare function without losing the effect of the present inventioncaused by the resin layer.

Conventionally, in an optical layered body with a configuration in whichan antistatic layer containing an antistatic agent is formed on thesurface of an antiglare layer having an uneven shape on the surface, itis difficult to satisfy the antiglare property owing to the antiglarelayer, the antistatic property owing to the antistatic layer, and thelight transmitting property which the optical layered body isintrinsically required to have. However, the optical layered body of thepresent invention can sufficiently satisfy these properties since it hasa desired resin layer on the rough surface under coat layer having theuneven shape as described.

The configuration in which the resin layer has the antiglare functionand the configuration in which a rough surface under coat layer havingan uneven shape is formed on the light transmitting substrate and theresin layer is formed on the rough surface under coat layer both mean alayer having an uneven shape on the surface (hereinafter, the layershaving both the configurations may be collectively referred to as anantiglare layer). The uneven shape preferably satisfies the followingexpression in which the average interval of the projections and recessesof the antiglare layer surface is expressed as Sm; the average slantingangle of the uneven part is expressed as θa; the arithmetic meanroughness of the unevenness is expressed as Ra; and the ten pointaverage roughness of the unevenness is expressed as Rz, in terms ofprevention of the reflection of the light from outside. If θa, Ra, andRz are less than their lower limits, reflection of light from outsidecannot be suppressed. If θa, Ra, and Rz exceed their upper limits, itmay result in an undesirable consequence such as scintillation. If Sm issmaller than its lower limit, white muddiness may possibly be caused. IfSm exceeds its upper limit, it may result in an undesirable consequencethat the reflection of light from outside cannot be suppressed.50 μm<Sm<600 μm0.1°<θa<1.5°0.02 μm<Ra<0.25 μm0.30 μm<Rz<2.00 μm

The uneven shape of the antiglare layer is more preferably satisfies thefollowing expression. If the following expression is satisfied, thereflection of light from outside can be prevented and it is madepossible to give excellent glossy blackness (reproducibility of wet lookglossy black color in image display) in the state of black display withan image display device and it is therefore more preferable. If θa, Ra,Rz and Sm exceed their upper limits or smaller than their lower limits,it may become impossible to give glossy blackness.100 μm<Sm<400 μm0.1°<θa<1.2°0.02 μm<Ra<0.15 μm0.30 μm<Rz<1.20 μm

In this description, Sm, Ra, and Rz are values measured by methodsaccording to JIS B 0601-1994; θa is a value obtained according to thedefinition in the manual instruction of a surface roughness measurementapparatus: SE-3400 (revised on Jul. 20, 1995) (Kosaka Laboratory Ltd.)and calculated as arc tangent {θa=tan⁻¹(h₁+h₂+h₃+ . . . +h_(n))/L} ofthe total of the height of the projections existing in a standard lengthL (h₁+h₂+h₃+ . . . +h_(n)) as shown in FIG. 2.

Sm, θa, Ra, and Rz can be calculated by using, for example, the surfaceroughness measurement apparatus: SE-3400 manufactured by KosakaLaboratory Ltd.

The uneven shape of the antiglare layer may be formed by using acomposition containing an antiglare agent, by phase separation of aresin, or by embossing process.

The uneven shape of the antiglare layer is more preferably formed byusing a composition containing an antiglare agent. In the case theantiglare layer is a resin layer having an uneven shape, the compositioncontaining the antiglare agent is the resin layer composition containingthe antiglare agent and is for forming the resin layer having an unevenshape. On the other hand, if the antiglare layer has a configuration inwhich the resin layer is formed on a rough surface under coat layer, thecomposition containing an antiglare agent is for forming the roughsurface under coat layer.

The antiglare agent is fine particles and the shape may be trulyspherical, elliptical, or amorphous, and the like and is notparticularly limited. Inorganic or organic fine particles may be used asthe antiglare agent and transparent fine particles are preferably used.

Specific examples of the organic fine particles include plastic beads.Examples of the plastic beads include polystyrene beads (refractiveindex 1.59 to 1.60), melamine beads (refractive index 1.57), acrylicbeads (refractive index 1.49 to 1.53), acrylic-styrene copolymer beads(refractive index 1.54 to 1.58), benzoguanamine-formaldehyde condensatebeads (refractive index 1.66), melamine-formaldehyde condensates(refractive index 1.66), polycarbonate beads (refractive index 1.57),and polyethylene beads (refractive index 1.50). The plastic beadspreferably have a hydrophobic group in their surfaces and for example,polystyrene beads are preferable.

Examples of the inorganic fine particles include amorphous silica andinorganic silica beads having a specified shape such as a sphericalshape.

Especially, it is preferable to use acrylic-styrene copolymer beadsand/or amorphous silica as the antiglare agent.

The average particle diameter of the antiglare agent is preferably 1 to10 μm and more preferably 3 to 8 μm. The average particle diameter is avalue measured by using a laser diffraction scattering particle sizeanalyzer in a dispersion state in 5 wt. % of toluene.

The content of the antiglare agent is preferably 1 to 40 parts by weightand more preferably 5 to 30 parts by weight relative to 100 parts byweight of the solid content of the binder resin.

The antiglare layer preferably further contains internally scatteredparticles. The internally scattered particles are those which canprovide internal haze and suppress scintillation and the like.

The internally scattered particles may be organic particles or inorganicparticles with a relatively large difference of refractive index fromthat of the binder resin composing the antiglare layer and examplesinclude plastic beads such as acrylic-styrene copolymer beads(refractive index 1.54 to 1.58), melamine beads (refractive index 1.57),polystyrene beads (refractive index 1.59 to 1.60), poly(vinyl chloride)beads (refractive index 1.60), benzoguanamine-formaldehyde condensatebeads (refractive index 1.66), and melamine-formaldehyde condensates(refractive index 1.66), and silicone particles (refractive index 1.42).

These particles may be those having properties as the antiglare agentand properties as the internally scattered particles.

The average particle diameter of the internally scattered particles ispreferably 0.5 to 10 μm and more preferably 1 to 8 μm. The averageparticle diameter is a value measured by using a laser diffractionscattering particle size analyzer in a dispersion state in 5 wt. % oftoluene.

The addition amount of the internally scattered particles is preferably0.1 to 40 wt. % and more preferably 1 to 30 parts wt. % relative to 100parts by weight of the solid content of the binder resin.

Those usable as a binder resin of the antiglare layer may be the same asthose usable as the binder resin of the resin layer.

The antiglare layer may further contain other components if necessary toan extent that the effect of the invention is not damaged. Those usableas other components may be the same as other components usable for theabove-mentioned resin layer.

The antiglare layer may be formed by a publicly known method. Forexample, a composition for an antiglare layer is prepared by mixing anddispersing a binder resin, an antiglare agent, other components and asolvent by a publicly known method. Those applicable as the method forpreparing the composition for an antiglare layer and the method offorming the antiglare layer using the composition may be the same asthose applicable as the method for preparing the resin layer compositionand the method of forming the resin layer, respectively.

The thickness of the antiglare layer is preferably 1 to 10 μm. If thethickness is smaller than 1 μm, the antiglare property may not beprovided sufficiently. If it is larger than 10 μm, curls or cracks maypossibly be formed.

The thickness of the layer is a value measured by observing a crosssection of the optical layered body with an electron microscope (SEM,TEM, STEM).

The optical layered body of the present invention preferably has a lowrefractive index layer on the resin layer since the antireflectionproperty can be improved.

The low refractive index layer is a layer playing a role of reducing thereflectance when the light from outside (e.g., a fluorescent lamp ornatural light) is reflected on the surface of the optical layered body.The low refractive index layer is preferably a thin film containing anyof 1) a resin containing silica or magnesium fluoride; 2) a fluorineresin, which is a low refractive index resin; 3) a fluorine resincontaining silica or magnesium fluoride; and 4) silica or magnesiumfluoride. Resins similar to the resins for composing the resin layer canbe used, except the fluorine resins.

The silica is preferably hollow silica fine particles and such hollowsilica fine particles can be produced by, for example, a productionmethod described in Examples of Japanese Kokai Publication 2005-099778.

The low refractive index layer preferably has a refractive index of 1.45or lower, more preferably 1.42 or lower.

The thickness of the low refractive index layer is not particularlylimited and in general, it may be set properly in a range of about 30 nmto 1 μm.

Although the low refractive index layer with a monolayer structure iseffective, it is also adequate to form 2 or more low refractive indexlayers in order to further reduce the minimum reflectance or furtherincrease the minimum reflectance. In the case of forming 2 or more lowrefractive index layers, it is preferable to make the refractive indexand thickness of the respective low refractive index layers different.

Examples of the fluorine resin include polymerizable compoundscontaining fluorine atoms at least in molecules and polymers thereof.The polymerizable compounds are not particularly limited, and thosehaving a functional group hardenable by ionizing radiation or ahardening-reactive group such as a thermosetting polar group arepreferable. Compounds having these reactive groups together are alsopreferable. In contrast to the polymerizable compounds, polymers arethose having no reactive group as described above.

Those widely usable as the polymerizable compounds having a functionalgroup hardenable by ionizing radiation may be fluorine-containingmonomers having an ethylenically unsaturated bond. More specifically,examples include fluoroolefins (e.g., fluoroethylene, vinylidenefluoride, tetrafluoroethylene, hexafluoropropylene, perfluorobutadiene,and perfluoro-2,2-dimethyl-1,3-dioxole). Those having a(meth)acryloyloxy group may be (meth)acrylate compounds having afluorine atom in the molecule such as 2,2,2-trifluoroethyl(meth)acrylate, 2,2,3,3,3-pentafluoropropyl (meth)acrylate,2-(perfluorobutyl)ethyl (meth)acrylate, 2-(perfluorohexyl)ethyl(meth)acrylate, 2-(perfluorooctyl)ethyl (meth)acrylate,2-(perfluorodecyl)ethyl (meth)acrylate, methyl α-trifluoromethacrylate,and ethyl α-trifluoromethacrylate; and fluorine-containingpolyfunctional (meth)acrylic acid ester compounds having a C₁₋₁₄fluoroalkyl group, a fluorocycloalkyl group, or a fluoroalkylene groupcontaining at least 3 fluorine atoms and also at least 2(meth)acryloyloxy groups in the molecule.

Those preferable as the thermosetting polar group are, for example,groups forming hydrogen bonds such as a hydroxyl group, a carboxylgroup, an amino group, and an epoxy group. These compounds are excellentnot only in the adhesiveness to a coating film but also in thecompatibility with inorganic ultrafine particles of silica or the like.Examples of the polymerizable compound having a thermosetting polargroup include a 4-fluoroethylene-perfluoroalkyl vinyl ether copolymer; afluoroethylene-hydrocarbon vinyl ether copolymer; and fluorine-modifiedproducts of epoxy, polyurethane, cellulose, phenol, and polyimideresins.

Examples of the polymerizable compounds having a functional grouphardenable by ionizing radiation and a thermosetting polar group includepartially or completely fluorinated alkyl acrylate or alkylmethacrylate; alkenyl and aryl esters; completely or partiallyfluorinated vinyl ethers; completely or partially fluorinated vinylesters; and completely or partially fluorinated vinyl ketones.

Examples of the fluorine resin are as follows. Polymers of monomers ormonomer mixtures containing at least one kind of fluorine-containing(meth)acrylate compounds among the polymerizable compounds having anionizing radiation hardenable group; copolymers of at least one kind ofcompound among the fluorine-containing (meth)acrylate compounds and(meth)acrylate compounds containing no fluorine atom in the moleculesuch as methyl (meth)acrylate, ethyl (meth)acrylate, propyl(meth)acrylate, butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate;and homo- or copolymers of fluorine-containing monomers such asfluoroethylene, vinylidene fluoride, trifluoroethylene,chlorotrifluoroethylene, 3,3,3-trifluoropropylene,1,1,2-trichloro-3,3,3-trifluoropropylene, and hexafluoropropylene.Silicone-containing vinylidene fluoride copolymers obtained by adding asilicone component to these copolymers are also usable. Examples of thesilicone component in this case include (poly)dimethylsiloxane,(poly)diethylsiloxane, (poly)diphenylsiloxane,(poly)methylphenylsiloxane, alkyl-modified (poly)dimethylsiloxane, azogroup-containing (poly)dimethylsiloxane, dimethylsilicone, phenyl methylsilicone, alkyl-aralkyl-modified silicone, fluorosilicone,polyether-modified silicone, fatty acid ester-modified silicone, methylhydrogen silicone, silanol group-containing silicone, alkoxygroup-containing silicone, phenol group-containing silicone,methacryl-modified silicone, acryl-modified silicone, amino-modifiedsilicone, carboxylic acid-modified silicone, carbinol-modified silicone,epoxy-modified silicone, mercapto-modified silicone, fluorine-modifiedsilicone, and polyether-modified silicone. Especially, those having adimethylsiloxane structure are preferable.

Further, non-polymers or polymers of the following compounds are alsousable as the fluorine resin. That is, compounds obtained by reaction offluorine-containing compounds having at least one isocyanato group inthe molecule with compounds having at least one functional groupreactive on the isocyanato group such as an amino group, a hydroxylgroup, and a carboxyl group in the molecule; and compounds obtained byreaction of fluorine-containing polyols such as fluorine-containingpolyether polyols, fluorine-containing alkyl polyols,fluorine-containing polyester polyols, fluorine-containing andδ-caprolactone-modified polyols with compounds having an isocyanatogroup.

Resin components as described above for the resin layer may also be usedtogether with the fluorine atom-containing polymerizable compounds andpolymers in the form of a mixture. A hardening agent for hardening thereactive groups or the like, and various kinds of additives and solventsfor improving the coatability and providing a stain-proofing propertymay be properly used.

In the case of forming the low refractive index layer, it is preferablethat the viscosity of the composition for a low refractive index layerobtained by adding the low refractive index agent and resins is adjustedto be in a range of preferably 0.5 to 5 mPa·s (25° C.) and morepreferably 0.7 to 3 mPa·s (25° C.) in which desirable coatability can beobtained. An antireflection layer excellent in the visible lightreflection can be realized and a uniform thin film with no coatingunevenness can be formed and thus a low refractive index layer excellentparticularly in the adhesiveness can be formed.

The hardening means of the resin may be the same as that described inthe above-mentioned resin layer. In the case a heating means is used forthe hardening treatment, it is preferable to add a heat polymerizationinitiator for starting the polymerization of the polymerizable compoundby heating to generate radicals to the fluorine resin composition.

The thickness (nm) d_(A) of the low refractive index layer preferablysatisfies the following expression (1):d _(A) =mλ/(4n _(A))  (1)wherein

n_(A) denotes the refractive index of the low refractive index layer;

m denotes a positive odd integer and is preferably 1;

λ denotes the wavelength and is preferable a value in a range of 480 to580 nm).

In the present invention, the low refractive index layer preferablysatisfies the following expression (2):120<n _(A) d _(A)<145  (2)in terms of decrease of the refractive index.

The optical layered body of the present invention may have otherarbitrary layers besides the light transmitting substrate, the resinlayer, and the antiglare layer. Examples of the arbitrary layers includea stain-proofing layer, a high refractive index layer, and a middlerefractive index layer. These layers may be formed by mixing a publiclyknown high refractive index agent and a stain-proofing agent with aresin, a solvent and the like and forming a layer by a publicly knownmethod.

The optical layered body of the present invention preferably has ahardness of 2H or higher in a pencil hardness test (load 4.9 N)according to JIS K5600-5-4 (1999).

The optical layered body of the present invention preferably has asurface resistance value of the resin layer (the initial valueimmediately after production) less than 1×10¹²Ω/□. If the surfaceresistance value is 1×10¹²Ω/□ or more, the intended antistatic functionmay not be exhibited. The surface resistance value is more preferablyless than 1×10¹¹Ω/□ and furthermore preferably less than 1×10¹⁰Ω/□.

The surface resistance value can be measured by a surface resistancemeasurement apparatus (product number: Hiresta UP MCP-HT 260,manufactured by Mitsubishi Chemical Corporation) using a UR probe andthe application voltage was set at 500 V.

The optical layered body of the present invention also preferably has aninitial surface resistance value of the outermost surface less than1×10¹²Ω/□ after 100 hours from a light resistance test (Fade-OMeter,FAL-AU-B, manufactured by Suga Test Instruments Co., Ltd.). If theinitial surface resistance value is 1×10¹²Ω/□ or more, the lightresistance such as ultraviolet resistance and oxidation resistance ofthe optical layered body of the present invention may possibly becomeinsufficient. The surface resistance value after the light resistancetest is more preferably less than 1×10¹¹Ω/□ and furthermore preferablyless than 1×10¹⁰Ω/□.

The Fade-Ometer is installed in a position at the ambient temperature of23° C. and a humidity of 65%. The sample size is adjusted by cutting theoptical layered body of the present invention in conformity to a sampleholder and a light source side is set in the resin layer side face of asample and the sample is fixed by using a presser plate and a spring.The irradiation intensity is 366 W/m² in a range of 300 to 400 nm and134 W/m² in a range of 400 to 700 nm.

The optical layered body of the present invention preferably has a totallight transmittance of 87.0% or more. If the total light transmittanceis smaller than 87.0%, in the case of installation in a display surface,the color reproducibility and visibility may possibly be deterioratedand it may be impossible to obtain desired contrast. The total lighttransmittance is more preferably 89.0% or more.

The total light transmittance can be measured by a method according toJIS K-7361 using a haze meter (product number: HM-150, manufactured byMurakami Color Research Laboratory).

The optical layered body of the present invention has a contrast ratioof preferably 80% or higher and more preferably 85% or higher. If thecontrast ratio is lower than 80%, the visibility may possibly be reducedin the case the optical layered body of the present invention isinstalled in a display surface. The contrast ratio in this descriptionis a value measured by the following method. Since the contrast ratiomeasured by the following method is 80% or higher, an image contrastrequired for a general image display device can be satisfied.

That is, using the one having a diffuser installed in a cold cathode raytube light source as a back light unit and 2 polarizers (AMN-3244TP,manufactured by Samsung), the contrast is defined as a value(L_(max)/L_(min)) calculated by dividing the luminance L_(max) of thelight passing when the polarizers are installed in a parallel Nicol'sprism by the luminance L_(min), of the light passing when the polarizersare installed in a cross Nicol's prism and the contrast (L₁) of theoptical layered body is measured by measuring the L_(max) and L_(min),from the resin layer side setting the optical layered body (lighttransmitting substrate+resin layer) in a manner that the lighttransmitting substrate is in the polarizer side. Next, the contrast (L₂)of the light transmitting substrate is calculated by respectivelymeasuring L_(max) and L_(min) arranging the light transmitting substrateon the polarizers. The value (L₁/L₂)×100(%) calculated by dividing (L₁)by (L₂) is defined as the contrast ratio.

For the measurement of the luminance, a color luminance meter (BM-5A,manufactured by Topcon Corporation) is used, and the measurement angleof the color luminance meter is set to be 1° and the visual field on asample is set to be ϕ5 mm. The light quantity of the back light is setin a manner that the luminance becomes 3600 cd/m² without setting asample when 2 polarizers are installed in a parallel Nicol's prism.

A method for producing an optical layered body of the present inventionmay be a method including a step of forming a resin layer using theresin layer composition.

The resin layer composition comprises a binder resin, a polythiophene,an auxiliary conductive agent, a leveling agent, and a solvent.

The present invention also includes the method for producing an opticallayered body.

The light transmitting substrate, the resin layer composition, and themethod of forming the resin layer are as described above.

Specifically, the method for producing an optical layered body of thepresent invention may be a method including the steps of forming a resinlayer on a light transmitting substrate using the resin layercomposition and forming a low refractive index layer on the resin layerif necessary. In the case of a configuration in which a resin layer isformed on the rough surface under coat layer, the method includes thesteps of forming the rough surface under coat layer and forming theresin layer on the rough surface under coat layer. The methods forforming the resin layer, the low refractive index layer, and the roughsurface under coat layer are as described above.

The optical layered body of the present invention can be used as apolarizer by forming the surface opposite to the surface where the resinlayer of the light transmitting substrate of the optical layered body onthe surface of a polarizing element. The present invention also includessuch a polarizer.

The polarizing element is not particularly limited and examples includea polyvinyl alcohol film, a polyvinyl formal film, a polyvinyl acetalfilm, and a saponified ethylene-vinyl acetate copolymer film which aredyed with iodine or the like and stretched. In the laminating treatmentof the polarizing element and the optical layered body, the lighttransmitting substrate is preferably saponified. The saponificationtreatment improves the adhesion property and also causes an antistaticeffect. A pressure-sensitive adhesive may be used for adhesion. Examplesof the pressure-sensitive adhesive include an acrylic pressure-sensitiveadhesive, a urethane pressure-sensitive adhesive, a siliconepressure-sensitive adhesive, and a water-based pressure-sensitiveadhesive.

The optical layered body and the polarizer of the invention may be seton the outermost surface of an image display device. The presentinvention also includes the image display device.

The image display device may be a non-self-emitting image display devicesuch as LCD; or a self-emitting image display device such as PDP, FED,ELD (organic EL, inorganic EL), or CRT.

LCD, one representative example of the non-self-emitting type, has alight transmitting display body and a light source apparatus forirradiating light from the back side of the light transmitting displaybody. In the case the image display device of the present invention isLCD, the optical layered body or the polarizer is formed on the surfaceof the light transmitting display body.

In the case of a liquid crystal display device having the opticallayered body of the present invention, the light source of a lightsource apparatus radiates light from the light transmitting substrateside of the optical layered body. In addition, for a STN type, VA type,or IPS type liquid crystal display device, a retardation plate may beinserted between the liquid crystal display element and the polarizer.If necessary, an adhesive layer may be formed between respectiveneighboring layers of the liquid crystal display device.

PDP, which is a self-emitting image display device, has a surface glasssubstrate (electrodes are formed on the surface) and a backplane glasssubstrate (electrodes and fine grooves are formed on the surface andred-, green-, and blue-emitting phosphor layers are formed in thegrooves) arranged on the opposite side to the surface glass substratewith an electric discharge gas enclosed in the space therebetween. Inthe case the image display device of the present invention is PDP, theoptical layered body is set on the surface of the surface glasssubstrate or its front plate (glass substrate or film substrate).

The self-emitting image display device may be an image display devicesuch as an ELD device for carrying out display by vapor-depositing alight emitting body such as zinc sulfide or a diamine substance whichemits light by voltage application on a glass substrate and controllingthe voltage applied to the substrate, or CRT for generating an imagevisible to human's eyes by converting electric signals to light rays. Inthis case, the optical layered body is set on the outermost surface orthe surface of the front plate of the respective display devicesdescribed above.

The optical layered body of the present invention can be used in anycase for display of a television, a computer, a mobile phone, or thelike. Particularly, the optical layered body can be used preferably forthe surface of a display for high definition images such as CRT, aliquid crystal panel, PDP, ELD, FED, a touch panel, or electronic paper.

Advantageous Effects of Invention

Having the above-mentioned configuration, an optical layered body of thepresent invention is made excellent in the antistatic property, has highimage contrast in the case of employed for an image display device, andis excellent in ultraviolet resistance and oxidation resistance whilekeeping conventional physical properties and optical properties.Accordingly, the optical layered body of the present invention can beused preferably for a cathode ray tube display device (CRT), a liquidcrystal display (LCD), a plasma display (PDP), an electroluminescencedisplay (ELD), a field emission display (FED), a touch panel, andelectronic paper.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1: A cross sectional SEM photograph of an optical layered body ofthe present invention having a resin layer containing chain ATO as anauxiliary conductive agent.

FIG. 2: An explanatory drawing for a method for measuring θa.

FIG. 3: A cross sectional drawing schematically showing a resin layer ofthe optical layered body of the present invention.

FIG. 4: A cross sectional drawing schematically showing a resin layer ofthe optical layered body of the present invention.

FIG. 5: A cross sectional drawing schematically showing a resin layer ofthe optical layered body of the present invention.

DESCRIPTION OF EMBODIMENTS

Hereinafter, the present invention will be described in more detail withreference to examples and comparative examples; however, the presentinvention should not be limited to those examples and comparativeexamples.

In the description, “part(s)” and “%” are on the basis of weight unlessotherwise specified.

Example 1

A light transmitting substrate (a triacetyl cellulose resin film with athickness of 80 μm, TD80 UL, manufactured by Fuji Film) was prepared anda resin layer composition having the composition described below wasapplied to one surface of the light transmitting substrate to form acoating film. Next, the formed coating film was dried in a hot oven at50° C. for 60 seconds to evaporate the solvent therefrom and hardened byirradiation with ultraviolet rays in the integrated light quantity of 50mJ/cm² to form a resin layer with a thickness of 4 μm (after hardening)and thus produce an optical layered body of Example 1.

(Resin Layer Composition)

PEDOT/PSS (organic solvent dispersion typepoly(3,4-ethylenedioxythiophene/polystyrenesulfonic acid) (CLEVIOS P;produced by H.C. Starck) 0.5 parts by weight

Chain ATO (V-3560; Chain ATO dispersion (non-volatile matter 20.5%),produced by JGC C&C) 1.2 parts by weight

Urethane acrylate (BS 577, hexa-functional, weight average molecularweight 1000 (containing 60% PETA in solid content), produced by ArakawaChemical Industries, Ltd.) 50.0 parts by weight

Acrylic ester (M-450, pentaerythritol tetraacrylate (PETTA), produced byToa Gosei Co., Ltd.) 45.0 parts by weight

Epoxy acrylate (Hitaloid 7851, produced by Hitachi Chemical Co., Ltd.)5.0 parts by weight

Polymerization initiator (Irgacure 184, produced by Ciba, Japan) 6.0parts by weight

Polyether-modified silicone oil (TSF 4460, produced by MomentivePerformance Materials, Japan) 1.0 part by weight

MIBK 150.0 parts by weight

n-BuOH 100.0 parts by weight

Example 2

An optical layered body of Example 2 was produced in the same manner asin Example 1, except that a resin layer composition prepared by mixing0.01 parts by weight of carbon nanotubes (VGCF-X, produced by ShowaDenko K.K.) was used in place of the chain ATO.

Example 3

An optical layered body of Example 3 was produced in the same manner asin Example 1, except that a resin layer composition prepared by mixing1.2 parts by weight of ATO (XJB-0014, produced by Pelnox Ltd.,non-volatile matter 30.0%) was used in place of the chain ATO.

Example 4

A light transmitting substrate (a triacetyl cellulose resin film with athickness of 80 μm, TD80 UL, manufactured by Fuji Film) was prepared anda resin layer composition having the composition described below wasapplied to one surface of the light transmitting substrate to form acoating film. Next, the formed coating film was dried in a hot oven at50° C. for 60 seconds to evaporate the solvent therefrom and hardened byirradiation with ultraviolet rays in the integrated light quantity of 50mJ/cm² to form a resin layer with a thickness of 6 μm (after hardening)and having an uneven shape in the surface and thus produce an opticallayered body of Example 4.

(Resin Layer Composition)

PEDOT/PSS (organic solvent dispersion typepoly(3,4-ethylenedioxythiophene/polystyrenesulfonic acid) (CLEVIOS P;produced by H.C. Starck) 0.5 parts by weight

Chain ATO (V-3560; Chain ATO dispersion (non-volatile matter 20.5%)produced by JGC C&C) 1.2 parts by weight

Urethane acrylate (BS 577, hexa-functional, weight average molecularweight 1000 (containing 60% PETA in solid content), produced by ArakawaChemical Industries, Ltd.) 50.0 parts by weight

Acrylic ester (M-450, pentaerythritol tetraacrylate (PETTA), produced byToa Gosei Co., Ltd.) 45.0 parts by weight

Epoxy acrylate (Hitaloid 7851, produced by Hitachi Chemical Co., Ltd.)5.0 parts by weight

Styrene-acrylic copolymer particles (average particle diameter 3.5 μm,refractive index 1.54, produced by Sekisui Plastics Co., Ltd.) 10.0parts by weight

Polymerization initiator (Irgacure 184, produced by Ciba, Japan) 6.0parts by weight

Polyether-modified silicone oil (TSF 4460, produced by MomentivePerformance Materials, Japan) 1.0 part by weight

MIBK 150.0 parts by weight

n-BuOH 100.0 parts by weight

Examples 5 and 6

Optical layered bodies of Examples 5 and 6 having an uneven shape in theresin layer surface were produced in the same manner as in Example 4,except that the addition amount of PEDOT/PSS, the kind of the auxiliaryconductive agent, and the addition amount of the auxiliary conductiveagent were changed as shown in the following Table 1.

In “kind of auxiliary conductive agent” in Table 1, the, “Carbonnanotubes” is VGCF-X (produced by Showa Denko K.K.) and “ATO” isXJB-0014 (produced by Pelnox Ltd., non-volatile matter 30.0%).

TABLE 1 Example 1 2 3 4 5 6 Layer Single Single Single Single SingleSingle configuration layer (H) layer (H) layer (H) layer (A) layer (A)layer (A) PEDOT/PSS 0.7 0.7  0.7 0.15 0.15 0.15 (parts by mass) Kind ofauxiliary Chain CNT ATO Chain CNT ATO conductive agent ATO ATO Auxiliary1.2 0.01 1.2 1.2  0.01 1.2  conductive agent (parts by mass) Singlelayer (H): resin layer is formed on light transmitting substrate. Singlelayer (A): resin layer having antiglare function is formed on lighttransmitting substrate.

Comparative Example 1

A resin layer was formed in the same manner as in Example 1 and anoptical layered body of Comparative Example 1 was produced, except thatno PEDOT/PSS was added and the addition amount of the auxiliaryconductive agent was changed as shown in the following Table 2.

Examples 7 to 18, Comparative Examples 2 to 4 and 6, and ExperimentalExamples 1 to 8

A light transmitting substrate (a triacetyl cellulose resin film with athickness of 80 μm, TD80 UL, manufactured by Fuji Film) was prepared anda composition for a rough surface under coat layer having thecomposition described below was applied to one surface of the lighttransmitting substrate to form a coating film.

(Composition for Rough Surface Under Coat Layer)

Acrylic-styrene copolymer beads (particle diameter 5 μm, refractiveindex 1.55, produced by Soken Chemical & Engineering Co., Ltd.) 15 partsby weight

Amorphous silica NIPGEL (AZ-204, average particle diameter 1.5 μm,produced by Tosoh Silica Co., Ltd.) 5 parts by weight

Pentaerythritol acrylate (PETA, PET-30, produced by Nippon Kayaku Co.,Ltd.) 100 parts by weight

Irgacure 184 (produced by Ciba, Japan) 6 parts by weight

Irgacure 907 (produced by Ciba, Japan) 1 part by weight

Polyether-modified silicone (TSF 4460, produced by Momentive PerformanceMaterials, Japan) 0.025 parts by weight

Toluene 150 parts by weight

Cyclohexanone 80 parts by weight

Next, the formed coating film was dried in a hot oven at 50° C. for 60seconds to evaporate the solvent therefrom and hardened by irradiationwith ultraviolet rays in the integrated light quantity of 30 mJ/cm² toform a rough surface under coat layer having a portion containing onlythe resin with a thickness of 3 μm (after hardening).

A resin layer was formed in the same manner as in Example 1, except thatthe addition amount of PEDOT/PSS, the kind of the auxiliary conductiveagent, and the addition amount of the auxiliary conductive agent in theresin layer composition were changed as shown in the following Table 2for formation of an upper layer of the rough surface under coat layerand thus optical layered bodies of respective examples, comparativeexamples, and experimental examples were produced.

In “kind of auxiliary conductive agent” in Table 2, “CNT” is carbonnanotubes (VGCF-X (produced by Showa Denko K.K.)) and “ATO” is XJB-0014(produced by Pelnox Ltd., non-volatile matter 30.0%).

Comparative Example 5, and Experimental Examples 9 and 10

A resin layer composition of Comparative Example 5 was prepared in thesame manner as in Example 1, except that no leveling agent was added.

A resin layer composition of Experimental Example 9 was prepared in thesame manner as in Example 1, except that no epoxy acrylate was added anda resin layer composition of Experimental Example 10 was prepared in thesame manner as in Example 1, except that only pentaerythritoltriacrylate (PETA, PET-30, produced by Nippon Kayaku Co., Ltd.) was usedas a binder resin.

Optical layered bodies of Comparative Example 7, Experimental Example 9,and Experimental Example 10 were produced in the same manner as inExample 12, except that the obtained resin layer compositions were used.

TABLE 2 Example 7 8 9 10 11 12 13 14 15 16 17 18 Layer Two Two Two TwoTwo Two Two Two Two Two Two Two configuration layer layer layer layerlayer layer layer layer layer layer layer layer PEDOT/PSS 0.5 0.5 0.50.5 0.5  0.5  0.5  0.5  0.5 0.5 0.5 0.5 (parts by mass) Kind ofauxiliary Chain Chain Chain Chain CNT CNT CNT CNT ATO ATO ATO ATOconductive agent ATO ATO ATO ATO Auxiliary 0.6 1.2 2.4 4.8 0.0015 0.010.02 0.12 0.6 1.2 2.4 4.8 conductive agent (parts by mass) ComparativeExample Example 1 2 3 4 5 6 1 2 3 4 5 6 7 8 9 10 Layer Single Two TwoTwo Two Two Two Two Two Two Two Two Two Two Two Two configuration layer(A) layer layer layer layer layer layer layer layer layer layer layerlayer layer layer layer PEDOT/PSS 0   0   0   0   0.5  0.5 0.05 1.3 0.50.5 0.5   0.5  0.5 0.5 0.5  0.5  (parts by mass) Kind of auxiliary ChainChain CNT ATO CNT None Chain Chain Chain Chain CNT CNT ATO ATO CNT CNTconductive agent ATO ATO ATO ATO ATO ATO Auxiliary 5.2 5.2 0.14 5.2 0.010   1.2  1.2 0.4 5.2 0.0005 0.14 0.4 5.2 0.01 0.01 conductive agent(parts by mass) Single layer (H): resin layer is formed on lighttransmitting substrate. Two layer: rough surface under coat layer andresin layer are formed on light transmitting substrate.

Example 19

A light transmitting substrate (a triacetyl cellulose resin film with athickness of 80 μm, TD80 UL, manufactured by Fuji Film) was prepared anda resin layer composition having the composition described below wasapplied to one surface of the light transmitting substrate to form acoating film. Next, the formed coating film was dried in a hot oven at50° C. for 60 seconds to evaporate the solvent therefrom and hardened byirradiation with ultraviolet rays in the integrated light quantity of 50mJ/cm² to form a resin layer with a thickness of 6 μm (after hardening)and having an uneven shape in the surface and thus produce an opticallayered body of Example 19.

(Resin Layer Composition)

PEDOT/PSS (organic solvent dispersion typepoly(3,4-ethylenedioxythiophene/polystyrenesulfonic acid) (CLEVIOS P;produced by H.C. Starck) 0.5 parts by weight

Chain ATO (V-3560; Chain ATO dispersion (non-volatile matter 20.5%)produced by JGC C&C) 1.2 parts by weight

Urethane acrylate (BS 577, hexa-functional, weight average molecularweight 1000 (containing 60% PETA in solid content), produced by ArakawaChemical Industries, Ltd.) 50.0 parts by weight

Acrylic ester (M-450, pentaerythritol tetraacrylate (PETTA), produced byToa Gosei Co., Ltd.) 45.0 parts by weight

Epoxy acrylate (Hitaloid 7851, produced by Hitachi Chemical Co., Ltd.)5.0 parts by weight

Styrene-acrylic copolymer particles (average particle diameter 3.5 μm,refractive index 1.54, produced by Sekisui Plastics Co., Ltd.) 10.0parts by weight

Polymerization initiator (Irgacure 184, produced by Ciba, Japan) 6.0parts by weight

Polyether-modified silicone oil (TSF 4460, produced by MomentivePerformance Materials, Japan) 1.0 part by weight

MIBK 150.0 parts by weight

n-BuOH 100.0 parts by weight

A composition for a low refractive index layer with the followingcomposition was applied to the outermost surface of the obtained resinlayer so that the film thickness after drying (40° C.×1 min) became 0.1μm. Thereafter, the coating film was hardened by ultraviolet rayirradiation with an irradiation intensity of 100 mJ/cm² using anultraviolet irradiation apparatus (light source H bulb, manufactured byFusion UV System, Japan) to obtain an optical layered body of Example19. The film thickness was adjusted in a manner that the minimum valueof the reflectance became around a wavelength of 550 nm.

(Composition for Low Refractive Index Layer)

Hollow silica fine particles (solid content of silica fine particles: 20wt. %, solution; methyl isobutyl ketone, average particle diameter: 50nm) 73 parts by weight

Fluorine atom-containing polymer (Opstar JN 35, produced by JSR,refractive index 1.41, weight average molecular weight 30000) 1 part byweight on the basis of solid content

Fluorine atom-containing monomer (LINC 3a, produced by Kyoeisha ChemicalCo., Ltd., reflective index 1.42) 7 parts by weight

Pentaerythritol acrylate (PETA, PET-30, produced by Nippon Kayaku Co.,Ltd.) 2 parts by weight

Polymerization initiator (Irgacure 127, produced by Ciba, Japan) 0.35parts by weight

Modified silicone oil (X 22164E; produced by Shin-Etsu Chemical Co.,Ltd) 0.5 parts by weight

Modified silicone oil (FM 7711; produced by Chisso Corporation) 0.5parts by weight

MIBK 320 parts by weight

PGMEA 161 parts by weight

Examples 20 and 21

A resin layer was formed in the same manner as in Example 19, exceptthat the type of the auxiliary conductive agent and the addition amountof the auxiliary conductive agent of the resin layer composition werechanged as shown in the following Table 3 and a low refractive indexlayer was formed under the same conditions as in Example 19 on theoutermost surface of the resin layer to produce optical layered bodiesof Examples 20 and 21.

In “kind of auxiliary conductive agent” in Table 3, “Carbon nanotubes”is VGCF-X (produced by Showa Denko K.K.) and “ATO” is XJB-0014 (producedby Pelnox Ltd., non-volatile matter 30.0%).

Example 22

A light transmitting substrate (a triacetyl cellulose resin film with athickness of 80 μm, TD80 UL, manufactured by Fuji Film) was prepared anda resin layer composition having the composition described below wasapplied to one surface of the light transmitting substrate to form acoating film. Next, the formed coating film was dried in a hot oven at50° C. for 60 seconds to evaporate the solvent therefrom and hardened byirradiation with ultraviolet rays in the integrated light quantity of 50mJ/cm² to form a resin layer with a thickness of 4 μm (after hardening).

Then, a low refractive index layer was formed under the same conditionsas in Example 19 on the outermost surface of the formed resin layer toproduce an optical layered body of Example 22.

(Resin Layer Composition)

PEDOT/PSS (organic solvent dispersion typepoly(3,4-ethylenedioxythiophene/polystyrenesulfonic acid) (CLEVIOS P;produced by H.C. Starck) 0.5 parts by weight

Chain ATO (V-3560; Chain ATO dispersion (non-volatile matter 20.5%)produced by JGC C&C) 1.2 parts by weight

Urethane acrylate (BS 577, hexa-functional, weight average molecularweight 1000 (containing 60% PETA in solid content), produced by ArakawaChemical Industries, Ltd.) 50.0 parts by weight

Acrylic ester (M-450, pentaerythritol tetraacrylate (PETTA), produced byToa Gosei Co., Ltd.) 45.0 parts by weight

Epoxy acrylate (Hitaloid 7851, produced by Hitachi Chemical Co., Ltd.)5.0 parts by weight

Polymerization initiator (Irgacure 184, produced by Ciba, Japan) 6.0parts by weight

Polyether-modified silicone oil (TSF 4460, produced by MomentivePerformance Materials, Japan) 1.0 part by weight

MIBK 150.0 parts by weight

n-BuOH 100.0 parts by weight

Examples 23 and 24

A resin layer was formed in the same manner as in Example 22, exceptthat the kind of the auxiliary conductive agent and the addition amountof the auxiliary conductive agent of the resin layer composition werechanged as shown in the following Table 3 and a low refractive indexlayer was formed under the same conditions as in Example 19 on theoutermost surface of the resin layer to produce optical layered bodiesof Examples 23 and 24.

In “kind of auxiliary conductive agent” in Table 3, “Carbon nanotubes”is VGCF-X (produced by Showa Denko K.K.) and “ATO” is XJB-0014 (producedby Pelnox Ltd., non-volatile matter 30.0%).

Example 25

A light transmitting substrate (a triacetyl cellulose resin film with athickness of 80 μm, TD80 UL, manufactured by Fuji Film) was prepared anda composition for a rough surface under coat layer having thecomposition described below was applied to one surface of the lighttransmitting substrate to form a coating film.

(Composition for Rough Surface Under Coat Layer)

Acrylic-styrene copolymer beads (particle diameter 5 μm, refractiveindex 1.55, produced by Soken Chemical & Engineering Co., Ltd.) 15 partsby weight

Amorphous silica NIPGEL (AZ-204, average particle diameter 1.5 μm,produced by Tosoh Silica Co., Ltd.) 5 parts by weight

Pentaerythritol acrylate (PETA, PET-30, produced by Nippon Kayaku Co.,Ltd.) 100 parts by weight

Irgacure 184 (produced by Ciba, Japan) 6 parts by weight

Irgacure 907 (produced by Ciba, Japan) 1 part by weight

Polyether-modified silicone (TSF 4460, produced by Momentive PerformanceMaterials, Japan) 0.025 parts by weight

Toluene 150 parts by weight

Cyclohexanone 80 parts by weight

Next, the formed coating film was dried in a hot oven at 50° C. for 60seconds to evaporate the solvent therefrom and hardened by irradiationwith ultraviolet rays in the integrated light quantity of 30 mJ/cm² toform a rough surface under coat layer having a portion containing onlythe resin with a thickness of 3 μm (after hardening).

A resin layer was formed in the same manner as in Example 1, except thatthe addition amount of PEDOT/PSS, the kind of the auxiliary conductiveagent, and the addition amount of the auxiliary conductive agent werechanged as shown in the following Table 3 for formation of an upperlayer of the rough surface under coat layer.

Then, a low refractive index layer was formed under the same conditionsas in Example 19 on the outermost surface of the formed resin layer toproduce an optical layered body of Example 25.

Examples 26 and 27

A rough surface under coat layer and a resin layer were formed in thesame manner as in Example 25, except that the addition amount ofPEDOT/PSS, the kind of auxiliary conductive agents, and the additionamount of the auxiliary conductive agent in the resin layer compositionwere changed as shown in the following Table 3. Then, a low refractiveindex layer was formed under the same conditions as in Example 19 on theoutermost surface of the formed resin layer to produce optical layeredbodies of Examples 26 and 27.

In “kind of auxiliary conductive agent” in Table 3, “Carbon nanotubes”is VGCF-X (produced by Showa Denko K.K.) and “ATO” is XJB-0014 (producedby Pelnox Ltd., non-volatile matter 30.0%).

TABLE 3 Example 19 20 21 22 23 24 25 26 27 Layer Single layer Singlelayer Single layer Single layer Single layer Single layer Two Two Twoconfiguration (A) + low (A) + low (A) + low (H) + low (H) + low (H) +low layers + low layers + low layers + low refractive refractiverefractive refractive refractive refractive refractive refractiverefractive index layer index layer index layer index layer index layerindex layer index layer index layer index layer PEDOT/PSS 0.5 0.5  0.50.5 0.5  0.5 0.5 0.5  0.5 (parts by mass) Kind of auxiliary Chain CNTATO Chain CNT ATO Chain CNT ATO conductive agent ATO ATO ATO Auxiliary1.2 0.01 1.2 1.2 0.01 1.2 1.2 0.01 1.2 conductive agent (parts by mass)Single layer (H): resin layer is formed on light transmitting substrate.Single layer (A): resin layer having antiglare function is formed onlight transmitting substrate. Two layer: rough surface under coat layerand resin layer are formed on light transmitting substrate.

The obtained optical layered bodies of Examples 1 to 27, ComparativeExamples 1 to 6, and Experimental Examples 1 to 10 were subjected to theevaluation of the following items. The evaluation results are shown inTable 4 and Table 5.

(Surface Resistance Value)

Regarding the surface resistance value of the surface of the resin layerof each of the obtained optical layered bodies, the initial surfaceresistance value immediately after the production was measured by usinga surface resistance measurement apparatus (product number: Hiresta IPMCP-HT260, manufactured by Mitsubishi Chemical Corporation). Regardingeach of the obtained optical layered bodies, the surface resistancevalue after 100 hours was measured by using Fade-OMeter (FAL-AU-B,manufactured by Suga Test Instruments Co., Ltd.) for light resistanceevaluation.

(Contrast Ratio)

In the contrast ratio measurement, using the one having a diffuserinstalled in a cold cathode ray tube light source as a back light unitand 2 polarizers (AMN-3244TP, manufactured by Samsung), the contrast(L₁) of the optical layered body (light transmitting substrate+resinlayer) and the contrast (L₂) of the light transmitting substrate weremeasured by dividing the L_(max) of the luminance of the light passingin the case the polarizers were installed in a parallel Nicol's prism bythe L_(min) of the luminance of the light passing in the case thepolarizers were installed in a cross Nicol's prism and the contrastratio was calculated according to (L₁/L₂)×100(%).

For the measurement of the luminance, a color luminance meter (BM-5A,manufactured by Topcon Corporation) was used. The measurement angle ofthe color luminance meter was set to be 1° and the measurement wascarried out in ϕ5 mm visual field on a sample. The light quantity of theback light was set in a manner that the luminance became 3600 cd/m₂without setting a sample when 2 polarizers were installed in a parallelNicol's prism.

(Total Light Transmittance)

The total light transmittance of each optical layered body was measuredby a method according to JIS K-7361 (total light transmittance) using ahaze meter (product number: HM-150, manufactured by Murakami ColorResearch Laboratory).

(Production Stability)

Each composition prepared in respective examples, comparative examples,and experimental examples was applied in a large size larger than 1 m²square; an arbitrary portion of 1 m² square in the plane was cut out;the obtained 1 m² square sheet was divided into 4 square portions toobtain sheet samples; the initial surface resistance value at anarbitrary position of each sample was measured by the same method asthat employed for the above-mentioned evaluation of the surfaceresistance; and each measured value was used for evaluation according tothe following standard.

Excellent: The number of points at which the surface resistance valuesdiffered in one digit order was 1 or less.

Good: The number of points at which the surface resistance valuesdiffered in one digit order was 2.

Poor: There were points at which the surface resistance values differedin two or more digit order.

(Comprehensive Evaluation)

Regarding the initial surface resistance value, the surface resistancevalue after the light resistance test, the contrast ratio, and the totallight transmittance, the respective evaluations for the comprehensiveevaluation were carried out as follows and each optical layered body ofrespective examples, comparative examples, and experimental examples wascomprehensively evaluated as follows.

(Individual Evaluation)

(1) Initial Surface Resistance Value and Surface Resistance Value afterLight Resistance Test

Excellent: less than the order of 1×10¹¹Ω/□

Good: less than the order of 1×10¹²Ω/□

Poor: equal to or more than the order of 1×10¹²Ω/□

(2) Contrast Ratio

Excellent: equal to or higher than 85%

Good: equal to or higher than 80% and lower than 85%

Poor: lower than 80%

(3) Total Light Transmittance

Excellent: equal to or higher than 89%

Good: equal to or higher than 87% and lower than 89%

Poor: lower than 87%

(Comprehensive Evaluation)

Excellent: All of the individual evaluations and production stabilitywere marked with Excellent

Good: There was at least one marked with Good among the individualevaluations and production stability

Poor: There was at least one marked with Poor among the individualevaluations and production stability

TABLE 4 Initial surface Total light resistance value Light resistance(100 h) Contrast ratio transmittance Production Comprehensive (Ω/□)Surface resistance (Ω/□) (%) (%) stability evaluation Example 1 8.00 ×10⁸ 9.00 × 10⁸ 86 89.2 Excellent Excellent 2 2.00 × 10⁹ 4.00 × 10⁹ 8990.0 Excellent Excellent 3 1.00 × 10⁹ 3.00 × 10⁹ 87 89.8 ExcellentExcellent 4  2.00 × 10¹⁰  5.00 × 10¹⁰ 96 91.2 Excellent Excellent 5 4.00 × 10¹⁰  6.00 × 10¹⁰ 97 91.3 Excellent Excellent 6  1.00 × 10¹⁰ 4.00 × 10¹⁰ 97 91.1 Excellent Excellent 7 5.00 × 10⁹ 6.00 × 10⁹ 89 90.7Excellent Excellent 8 1.00 × 10⁹ 2.00 × 10⁹ 88 90.4 Excellent Excellent9 4.00 × 10⁸ 8.00 × 10⁸ 87 90.2 Excellent Excellent 10 2.00 × 10⁸ 6.00 ×10⁸ 85 89.5 Excellent Excellent 11 6.00 × 10⁹  1.00 × 10¹⁰ 91 90.8Excellent Excellent 12 3.00 × 10⁹ 5.00 × 10⁹ 90 90.6 Excellent Excellent13 9.00 × 10⁸ 2.00 × 10⁹ 89 90.2 Excellent Excellent 14 5.00 × 10⁸ 7.00× 10⁸ 87 89.0 Excellent Excellent 15  3.00 × 10¹⁰  4.00 × 10¹⁰ 89 90.6Excellent Excellent 16 3.00 × 10⁹ 5.00 × 10⁹ 88 90.3 Excellent Excellent17 9.00 × 10⁸ 3.00 × 10⁹ 87 90.1 Excellent Excellent 18 5.00 × 10⁸ 6.00× 10⁸ 85 90.0 Excellent Excellent Comparative 1 ND — — 90.0 — PoorExample 2 ND — — 90.0 — Poor 3 ND — — 91.7 — Poor 4 ND — — 89.9 — Poor 51.00 × 10⁹ ND 90 90.6 Good Poor 6 ND ND 90 90.6 Poor Poor Example 1 6.00 × 10¹¹  9.00 × 10¹¹ 98 91.4 Good Good 2 5.00 × 10⁸ 8.00 × 10⁸ 8187.5 Excellent Good 3  5.00 × 10¹¹  8.00 × 10¹¹ 91 90.9 Good Good 4 1.00× 10⁸ 5.00 × 10⁸ 81 87.7 Excellent Good 5  3.00 × 10¹¹  7.00 × 10¹¹ 9291.0 Good Good 6 4.00 × 10⁸ 6.00 × 10⁸ 84 88.6 Excellent Good 7  4.00 ×10¹¹  7.00 × 10¹¹ 90 90.9 Good Good 8 4.00 × 10⁸ 5.00 × 10⁸ 80 87.1Excellent Good 9  1.00 × 10¹¹  5.00 × 10¹¹ 90 90.6 Good Good 10 ND — 9090.6 — Poor “ND” indicates that measurement could not be performed orthe value was out the range (resistance value was 10¹⁴ Ω/□ or higher).

TABLE 5 Initial surface Total light resistance value Light resistance(100 h) Contrast ratio transmittance Production Comprehensive (Ω/□)Surface resistance (Ω/□) (%) (%) stability evaluation Example 19 6.00 ×10⁹ 8.00 × 10⁹ 93 93.3 Excellent Excellent 20 8.00 × 10⁹ 9.00 × 10⁹ 9493.2 Excellent Excellent 21 7.00 × 10⁹ 7.00 × 10⁹ 93 93.3 ExcellentExcellent 22 5.00 × 10⁹ 7.00 × 10⁹ 93 94.0 Excellent Excellent 23 7.00 ×10⁹ 8.00 × 10⁹ 95 94.1 Excellent Excellent 24 6.00 × 10⁹ 7.00 × 10⁹ 9494.0 Excellent Excellent 25 7.00 × 10⁹ 8.00 × 10⁹ 92 93.1 ExcellentExcellent 26 8.00 × 10⁹ 9.00 × 10⁹ 92 93.1 Excellent Excellent 27 7.00 ×10⁹ 7.00 × 10⁹ 92 93.1 Excellent Excellent

As shown in Tables 4 and 5, the initial surface resistance value, thesurface resistance value after the light resistance test, the contrastratio, and the total light transmittance showed similar tendencyregardless of the kinds of the auxiliary conductive agents if thecontent of the auxiliary conductive agent was around a preferable range.

As shown also in Tables 4 and 5, all the optical layered bodies ofexamples were found excellent in light resistance and antistaticproperty and had desired high contrast while maintaining excellentoptical properties.

With respect to monolayer ones, bilayer ones, and those having a lowrefractive index layer formed additionally, no significant difference ofeffect was observed among them.

The optical layered bodies having an antiglare function of Examples 4 to21 and 25 to 27, and Experimental Examples 1 to 10 all satisfied therespective requirements for the surface uneveness form, that is, 50μm<Sm<600 μm, 0.1°<θa<1.5°, 0.02 μm<Ra<0.25 μm, and 0.30 μm<Rz<2.00 μmand had excellent optical properties.

The optical layered bodies of Examples 19 to 27 in which the lowrefractive index layer was formed were all found to have an extremelylow value of the minimum reflectance as low as 0.8 to 1.1% and thus hadmore excellent optical properties.

On the other hand, the optical layered bodies of Comparative Examples 1to 4 had a poor initial surface resistance value and were insufficientin the antistatic property, since they contained no polythiophene. Sincecontaining no auxiliary conductive agent, the optical layered body ofComparative Example 6 had a poor initial surface resistance value and apoor surface resistance value after the light resistance test and wasinsufficient in the antistatic property and inferior in the productionstability. The optical layered body of Comparative Example 5, whichcontained no leveling agent, was insufficient in the surface resistancevalue after the light resistance test although the initial surfaceresistance value was better than normal and inferior in the productionstability, since the polythiophene unevenly existed near the outermostsurface layer of the resin layer and also the auxiliary conductive agentwas not arranged in proper positions defined in the present invention.In addition, in all of examples and experimental examples excludingExperimental Example 10, the polythiophene and auxiliary conductiveagent were positioned at proper positions defined in the presentinvention and the initial surface resistance value and surfaceresistance value after a light resistance test were satisfactory.

The optical layered body of Experimental Example 1, which contained onlya small amount of the polythiophene, was poor in the initial surfaceresistance value and surface resistance value after the light resistancetest and was not provided with a sufficient antistatic property. On theother hand, the optical layered body of Experimental Example 2, whichcontained too large an amount of the polythiophene, was not providedwith the desired high contrast. The optical layered bodies ofExperimental Examples 3, 5, and 7, which contained only a small amountof the auxiliary conductive agent, were poor in the initial surfaceresistance value and surface resistance value after the light resistancetest and insufficient in the antistatic property. On the other hand, theoptical layered bodies of Experimental Examples 4, 6, and 8, whichcontained a large amount of the auxiliary conductive agent, were notprovided with the desired high contrast or desired high total lighttransmittance. The optical layered body of Experimental Example 9, forwhich no additive having a protonic functional group (epoxy acrylate)was added, was slightly inferior in the dispersibility and stability ofthe polythiophene and slightly inferior in the initial surfaceresistance value and surface resistance value after the light resistancetest. The optical layered body of Experimental Example 10, for whichonly PETA, a highly polar hydrophobic resin, was used as a binder resin,was insufficient in the initial surface resistance.

INDUSTRIAL APPLICABILITY

The optical layered body of the present invention can be used preferablyfor a cathode ray tube display device (CRT), a liquid crystal display(LCD), a plasma display (PDP), an electroluminescence display (ELD), afield emission display (FED), a touch panel, electronic paper, and thelike.

The invention claimed is:
 1. An optical layered body having a lighttransmitting substrate and a resin layer formed on one surface of saidlight transmitting substrate, wherein said resin layer comprises abinder resin, a polythiophene, an auxiliary conductive agent, a levelingagent, and an additive having a protonic functional group which carriesout a cross-linking reaction, a rough surface under coat layer isfurther formed between the light transmitting substrate and the resinlayer, the auxiliary conductive agent is carbon nanotubes, the resinlayer has an antiglare function, the resin layer having an antiglarefunction has an uneven surface shape, the uneven shape of the resinlayer satisfies the following expression in which the average intervalof the projections and recesses of the resin layer surface is expressedas Sm; the average slanting angle of the uneven part is expressed as θa;the arithmetic mean roughness of the unevenness is expressed as Ra; andthe ten point average roughness of the unevenness is expressed as Rz: 50μm<Sm<600 μm 0.1°<θa<1.50° 0.02 μm<Ra<0.25 μm 0.30 μm<Rz<2.00 μm; theresin layer is composed of a single layer and has a first regioncontaining no auxiliary conductive agent from the interface on theopposite side to the light transmitting substrate to 100 nm; and theresin layer further comprises: (i) a second region wherein the auxiliaryconductive agent exists from the interface of the resin layer on thelight transmitting substrate side and a third region wherein thepolythiophene exists and being located between the first region and thesecond region, or (ii) a second region wherein the auxiliary conductiveagent exists from the interface of the resin layer on the lighttransmitting substrate side and a third region wherein the auxiliaryconductive agent and polythiophene exist and being located between thefirst region and the second region.
 2. The optical layered bodyaccording to claim 1, wherein the content of the polythiophene is 0.1 to1.0 part by weight relative to 100 parts by weight of the binder resin.3. The optical layered body according to claim 1, wherein thepolythiophene is a complex with an anionic compound.
 4. The opticallayered body according to claim 1, wherein the auxiliary conductiveagent is carbon nanotubes and the content of said auxiliary conductiveagent is 0.001 to 0.13 parts by weight relative to 100 parts by weightof the binder resin.
 5. The optical layered body according to claim 1,wherein the initial surface resistance value and the surface resistancevalue after a light resistance test of the resin layer are less than1×10¹²Ω/□.
 6. The optical layered body according to claim 1, wherein theadditive having a protonic functional group is epoxy acrylate.
 7. Apolarizer having a polarizing element, wherein said polarizer has theoptical layered body according to claim 1, on a surface of saidpolarizing element.
 8. An image display device having the opticallayered body according to claim 1 or the polarizer according to claim 7on an outermost surface.
 9. The optical layered body according to claim2, wherein the polythiophene is a complex with an anionic compound. 10.The optical layered body according to claim 2, wherein the initialsurface resistance value and the surface resistance value after a lightresistance test of the resin layer are less than 1×10¹²Ω/□.
 11. Theoptical layered body according to claim 3, wherein the initial surfaceresistance value and the surface resistance value after a lightresistance test of the resin layer are less than 1×10¹²Ω/□.